• WordNet 3.6
    • n ovum the female reproductive cell; the female gamete
    • ***
Webster's Revised Unabridged Dictionary
  • Interesting fact: The largest cell in the human body is the female ovum, or egg cell. It is about 1/180 inch in diameter. The smallest cell in the human body is the male sperm. It takes about 175,000 sperm cells to weigh as much as a single egg cell.
    • Ovum (Biol) A more or less spherical and transparent cell, which by a process of multiplication and growth develops into a mass of cells, constituting a new individual like the parent; an egg, spore, germ, or germ cell. See Illust. of Mycropyle.
    • Ovum (Arch) One of the series of egg-shaped ornaments into which the ovolo is often carved.
    • ***
Century Dictionary and Cyclopedia
  • Interesting fact: The largest cell in the human body is the female reproductive cell, the ovum. The smallest is the male sperm.
    • n ovum An egg, in a broad biological sense; the proper product of an ovary; the female germ or seed, which when fertilized by the male sperm, and sometimes without such fecundation, is capable of developing into an individual like the parent. There is agreat similarity in the ova of different animals throughout the metazoic series, from the sponge to the human being, no ova in their early stages being distinguishable from one another in their essential characters. All true ova, as distinguished from spores and products of fission or gemmation, are referable to the single morphological type of the cell; and they are furthermore indistinguishable from unicellular animals, and from many of the cells composing the bodies of the higher animals. An ovum consists of a quantity of protoplasm or cell-substance called the vitellus or yolk, inclosed in a cell-wall or vitelline membrane, and provided with a nucleus and usually a nucleolus; it is engendered in the ovarium, usually in an ovisac or so-called Graafian follicle, is discharged from itsmatrix, usually then meeting with the male element, and proceeds to develop within or without the body of the parent. The ovum proper. like most cells, is usually of microscopic size; but its bulk may be enormously increased by the addition of extrinsic or adventitious protoplasmic or albuminous substance, and it may be further protected by various kinds of egg-pod or egg-shell, all without losing its essential character as a cell. The largest ova, relatively and absolutely, are birds' eggs, these being by far the largest cells known in the animal kingdom. Here the quantity of food-yolk which does not undergo transformation into the body of the chick is out of all proportion to the formative yolk proper, which makes only a speck in the great ball of “yellow” and “white.” Such ova are called meroblastic, in distinction from holoblastic. The human ovum is very minute, relatively and absolutely, averaging about of an inch in diameter. It is said to have been first recognized by K. E. von Baer in 1827. The parts of the ovum have been badly named, without reference to its morphology as a cell. Thus, the cell-wall is called the zona pellucida; the nucleus is named the germinal vesicle or vesicle of Purkinje, and its nucleolus the germinal spot or spot of Wagner. The phrases germinal vesicle and germinal spot are misleading. The first stages of development of an ovum, consequent upon fertilization, consist in the segmentation of the vitellus, or yolk-division, by which the cell-substance becomes a mulberry-mass of spherules, called the morula. The rest is an intricate process of differentiation and specialization of these spherules, and their multiplications into the myriads of different kinds of cells of which the whole body of most adult animals is fabricated. Some of the early special stages of this process are known as the morula, gastrula, blastula, etc. The first tissue or coherent layer of cells produced is called a blastoderm. When there are two layers, inner and outer blastodermic layers, they are distinguished as endoderm and ectoderm; when a third intermediate layer is formed, it is the mesoderm. An ovum is called, in general, a germ until the rudiments of its specific characters appear, when it becomes an embryo, and later may be a fetus. That department of ontology which treats of the development of the ovum is embryology. See cuts under diphyzoöid, gastrulation, gonophore, and ovotestis.
    • n ovum [capitalized] In conchology, same as Ovulum.
    • n ovum [capitalized] In ichthyology, a genus of fishes.
    • n ovum In architecture, an ornament in the shape of an egg.
    • ***
Chambers's Twentieth Century Dictionary
    • n Ovum ō′vum an egg:
    • n Ovum ō′vum (biol.) the egg-cell, in all organisms the starting-point of the embryo, development beginning as soon as it is supplemented by the male-cell or spermatozoon
    • ***


Webster's Revised Unabridged Dictionary
L., an egg. See Oval
Chambers's Twentieth Century Dictionary


In literature:

There are no blood cells in a sperm, and I don't think there are any in an ovum.
"The Galaxy Primes" by Edward Elmer Smith
The ripening follicle moves to the surface of the ovary and bursts, the ovum falls into the body cavity.
"Text Book of Biology, Part 1: Vertebrata" by H. G. Wells
Follicle from which the ovum has escaped.
"Woman" by William J. Robinson
There are in the germ and the ovum which constitute the inheritance of each individual, certain determinant elements.
"Human Traits and their Social Significance" by Irwin Edman
It is then shed not as a mere ovum, but as an animal nearly or wholly complete.
"A Theory of Creation: A Review of 'Vestiges of the Natural History of Creation'" by Francis Bowen
The thumb is then replaced over the end of the tube, which is lifted from the water with the ovum retained in it.
"Amateur Fish Culture" by Charles Edward Walker
The immature male (32833), the large size of ovum (8 mm.
"Birds from Coahuila, Mexico" by Emil K. Urban
In the larger ones, as the horse and the cow, but one ovum generally develops, though the development of two is not uncommon.
"The Renewal of Life; How and When to Tell the Story to the Young" by Margaret Warner Morley
The third, when abortion must take place, to expedite the separation of the ovum and free the contents of the womb.
"The Ladies Book of Useful Information" by Anonymous
And as the rose springs from the seed, so the horse develops from the ovum.
"The Heart of Nature" by Francis Younghusband

In poetry:

But remember, O dealer in phrases sonorous,
So daintily chosen, so tunefully matched,
Though you soar with the wings of the cherubim o'er us,
The ovum was human from which you were hatched.
"A Familiar Letter" by Oliver Wendell Holmes

In news:

Ovum Outlines Criteria for Organizations Considering a Hosted Call Center.
Ovum comments on iPhone 5's 4G capability in the UK.
The Asia-Pacific region could overtake North America as the top market for service provider switches and routers, according to Ovum 's latest report.
Internet Traffic Driving Demand for Service Provider Networking Gear: Ovum .
Google's Android platform may surpass Apple's iOS in developer interest in the next 12 months, according to Ovum .
Yet Ovum also sees Microsoft Windows Phone and RIM's BlackBerry OS as viable options.
Android to Supplant iOS Among Developers: Ovum .
Ovum and IBM to Discuss Systems Engineering in Free Webinar.
LOS ALAMITOS, Calif, 16 November, 2011 – Ovum Principal Analyst Tony Baer and IBM Program Director Dominic Tavassoli will hold a Coffee Break Chat tomorrow on systems engineering.
Ovum endorses Hitachi ID Systems solutions.
There will be an uptick in IT spending in 2010, but those budgets that do grow will increase by only 1 to 5 percent, according to Ovum .
The bulk of CIOs in an Ovum survey said they expect their budgets to remain flat after the recession-ravaged 2009.
IT Spending in 2010 Will Rise Slightly: Ovum .
The Publication of Ovum Humanum.
Google's Android platform may surpass Apple's iOS in developer interest in the next 12 months, according to Ovum.

In science:

Our world is filled with swimming microorganisms: The spermatozoon that fuse with the ovum during fertilization, the bacteria that inhabit our guts, the protozoa in our ponds, and the algae in the ocean.
The hydrodynamics of swimming microorganisms
The spermatozoa of many organisms swim to the ovum, sometimes in challenging environments such as tidal pools in the case of sea urchins or cervical mucus in the case of humans .
The hydrodynamics of swimming microorganisms
In addition to the mucus at the cervix and in the uterine cavity, sperm must also penetrate the matix coating the ovum, known as the cumulus oophorus, which is a viscoelastic actin-based gel [248].
The hydrodynamics of swimming microorganisms
In such a population nearly all individuals have the same bit-strings A and A’ in their diploid genome, thus producing haploid gametes (ovum and sperm cells) of one type only, either A or A’.
Review of haplotype complementarity under mutational pressure
An A sperm combined with an ovum of gamete type A cannot survive with many mutations, since then even homozygous pairs of recessive alleles affect our health.
Review of haplotype complementarity under mutational pressure