• WordNet 3.6
    • n stratum an abstract place usually conceived as having depth "a good actor communicates on several levels","a simile has at least two layers of meaning","the mind functions on many strata simultaneously"
    • n stratum people having the same social, economic, or educational status "the working class","an emerging professional class"
    • n stratum one of several parallel layers of material arranged one on top of another (such as a layer of tissue or cells in an organism or a layer of sedimentary rock)
    • ***
Webster's Revised Unabridged Dictionary
  • Interesting fact: The tips of fingers and the soles of feet are covered by a thick, tough layer of skin called the stratum corneum.
    • Stratum (Geol) A bed of earth or rock of one kind, formed by natural causes, and consisting usually of a series of layers, which form a rock as it lies between beds of other kinds. Also used figuratively.
    • Stratum A bed or layer artificially made; a course.
    • ***
Century Dictionary and Cyclopedia
    • n stratum A layer of material, formed either naturally or artificially. Specifically— In geology, same as bed. See bed, 6 , and stratification, also cut under Artesian.
    • n stratum In archæol. excavations, one of the layers of deposits left by successive civilizations, as in the overlying cities at Hissarlik, the ancient Troy.
    • ***
Chambers's Twentieth Century Dictionary
    • n Stratum strā′tum a bed of earth or rock formed by natural causes, and consisting usually of a series of layers: any bed or layer
    • ***


Webster's Revised Unabridged Dictionary
L., from sternere, stratum, to spread; akin to Gr. to spread, strew. See Strew, and cf. Consternation Estrade Prostrate Stratus Street
Chambers's Twentieth Century Dictionary
L. stratumsternĕre, stratum, to spread out.


In literature:

What a God-send for us that there happens to be, just here, this stratum of soft sand.
"The Mistress of Shenstone" by Florence L. Barclay
It was set on a shelf of one stratum of rock, and roofed over by another.
"Our Bird Comrades" by Leander S. (Leander Sylvester) Keyser
The pileus is somewhat pliant when moist or wet, and firm when dry, the dark inner stratum hard.
"Studies of American Fungi. Mushrooms, Edible, Poisonous, etc." by George Francis Atkinson
The method of the meadow mice is between these two: its stratum of active life is above the mole and beneath the chipmunk.
"The Log of the Sun" by William Beebe
Through the surface stratum of earth it went, and bang it came against the sandstone.
"The Humbugs of the World" by P. T. Barnum
There is somewhere or other a stratum of English society in which such a code already exists.
"Modern Women and What is Said of Them" by Anonymous
At nearly every step I took I came into a different stratum or perpendicular layer of air.
"Shapes that Haunt the Dusk" by Various
This heavy stratum is the most impressive part of the Glacier landscape.
"The Book of the National Parks" by Robert Sterling Yard
The general tone of these little societies represents, of course, the tendency of the upper stratum of the industrial classes.
"The English Utilitarians, Volume I." by Leslie Stephen
The intermediate stratum of soil, situated from 25 to 50 cm.
"The Elements of Bacteriological Technique" by John William Henry Eyre
They came from over in Illinois somewhere, and I guess the clay's off the very same stratum.
"Otherwise Phyllis" by Meredith Nicholson
Even at the close of the Oolitic period this sepulchral stratum must have been a profoundly ancient one.
"The Cruise of the Betsey" by Hugh Miller
Just under the summit the rock-stratum emerged in mass, and on one side the earth yawned in a hole.
"Hurricane Island" by H. B. Marriott Watson
A society clique too closely imitated by a lower stratum must regain its distinction and supremacy.
"Introduction to the Science of Sociology" by Robert E. Park
In the Polyporus the stratum of tubes cannot be separated.
"The Mushroom, Edible and Otherwise" by M. E. Hard
And it was from this particular stratum that the barkeeper at The Mint had derived his moral concepts.
"Wunpost" by Dane Coolidge
Never before had he seen a couple dressed like these; he had struck a new stratum.
"The Works of Robert Louis Stevenson - Swanston Edition Vol. 7 (of 25)" by Robert Louis Stevenson
But it was the deeper stratum of oblivion that had to be reached, without dynamite if possible.
"When Ghost Meets Ghost" by William Frend De Morgan
The new officials were selected from every walk of life, from every shade of opinion, from every stratum of society.
"The Life of Napoleon Bonaparte" by William Milligan Sloane
The second stratum of flowing sand began just below where the lock floor had to be laid.
"The Industrial Canal and Inner Harbor of New Orleans" by Thomas Ewing Dabney

In poetry:

Say I: "O labor, to despoil
Some lovely forest scene,
Or at the granite stratum toil,
And desecrate whole roods of soil,
Is vandal-like and mean!
"Improvement." by Hattie Howard
"Speak, O man, less recent! Fragmentary fossil!
Primal pioneer of pliocene formation,
Hid in lowest drifts below the earliest stratum
Of volcanic tufa!
"To The Pliocene Skull" by Francis Bret Harte
Come up out of Erebus into the day,
There's plenty of room overhead;
No boring or blasting of rocks in the way,
No stratum of sticky, impervious clay--
All vacuous vapor instead.
"The Subway" by Hattie Howard

In news:

In terms of lifestyle, dictators and rock stars occupy the same stratum.
Researchers at Karolinska Institutet in Sweden have succeeded in describing the structure and function of the stratum corneum at a molecular level.
Superficial fungal infections arise from a pathogen that is restricted to the stratum corneum, with little or no tissue reaction.
Stratum Corneum Described at the Molecular Level.
But perhaps more promising for the industry is the growing "middle class" stratum of buyers, like Kevin Plank and vitaminwater founder, Mike Repole, who are taking a slow, steady and smart approach to building their horse-racing entities.

In science:

For abelian gauge theories the generic stratum is globally trivial and equals the total space A.
On the Gribov Problem for Generalized Connections
However, for a certain class of non-abelian gauge theories – e.g., all SU (N ) theories – the generic stratum is nontrivial.
On the Gribov Problem for Generalized Connections
Example 2 In the minimal stratum we have Z (HA) = G.
On the Gribov Problem for Generalized Connections
Proof By the definition of the gauge orbit type, all holonomy centralizers Z (HA ) occurring in a fixed stratum A=t are conjugate.
On the Gribov Problem for Generalized Connections
Now we want to know when the generic stratum is nontrivial.
On the Gribov Problem for Generalized Connections
The orbits in the generic stratum are isomorphic to SU (2)/Z2 , i.e. are three-dimensional.
On the Gribov Problem for Generalized Connections
Next, we shall find a continuous section in the generic stratum of SU (2)2 .
On the Gribov Problem for Generalized Connections
We will show here that the adjoint action on SU (2)3 leads to a nontrivial generic stratum.
On the Gribov Problem for Generalized Connections
In the case l < n, this is the only stratum which contributes to j ∗Φ∗ [X ]T , giving us (a).
Some applications of localization to enumerative problems
So for some positive k , L(H)(k) separates the points of every stratum of ˜X /R.
Compactifications defined by arrangements I: the ball quotient case
For that reason these meromorphic functions also separate the points of any stratum T (σ)◦ .
Compactifications defined by arrangements I: the ball quotient case
To see Its orbifold structure is that, consider the singular stratum of M .
Orbispaces and Orbifolds from the Point of View of the Borel Construction, a new Definition
This implies G-normality, since every fixed point of g comes from a stratum that corresponds to some cone of ∆.
McKay correspondence for elliptic genera
We will argue by induction on the dimension of the stratum.
McKay correspondence for elliptic genera
After an equivariant desingularization, we may assume that X is smooth and X1 is the open stratum.
McKay correspondence for elliptic genera