• WordNet 3.6
    • n quadruplet a set of four similar things considered as a unit
    • n quadruplet one of four children born at the same time from the same pregnancy
    • n quadruplet the cardinal number that is the sum of three and one
    • ***
Webster's Revised Unabridged Dictionary
  • Interesting fact: The odds of having quadruplets are 1 in 729,000
    • Quadruplet A collection or combination of four of a kind.
    • Quadruplet A cycle for carrying four riders, so arranged that all the riders can assist in the propulsion.
    • Quadruplet Four children born in the same labor.
    • ***
Century Dictionary and Cyclopedia
  • Interesting fact: The chances for a mother giving birth to quadruplets (four Childs) are almost 1 in 600,000.
    • n quadruplet Any combination of four objects or parts grouped, united, or acting together: as, a quadruplet of springs, consisting of four elliptic springs coupled together and acting as one spring. Also called quartet.
    • n quadruplet One of four born at a single birth.
    • n quadruplet A bicycle for four riders.
    • n quadruplet In music, same as quartole.
    • ***
Chambers's Twentieth Century Dictionary
  • Interesting fact: When armadillos are pregnant they always have quadruplets of the same sex.
    • n Quadruplet any combination of four things—also Quart′et: one of four born at a birth
    • ***


Webster's Revised Unabridged Dictionary
From Quadruple
Chambers's Twentieth Century Dictionary
Fr.,—L. quadruplusquatuor, four.


In literature:

Quadruplets are supposed to occur once in about every 400,000 births.
"Anomalies and Curiosities of Medicine" by George M. Gould
My mother's name was Martha and I am one of quadruplets, three girls and one boy, that's me.
"Slave Narratives: A Folk History of Slavery in the United States From Interviews with Former Slaves: Volume II, Arkansas Narratives, Part 2" by Work Projects Administration
The father of the quadruplets is one of twelve children, among whom is one pair of twins.
"Applied Eugenics" by Paul Popenoe and Roswell Hill Johnson
He ducked around her, moving quickly past four linked Siamese quadruplets who stared at him with huge mournful eyes.
"The Status Civilization" by Robert Sheckley
Instances of quadruplets are fewer than triplets.
"The Physical Life of Woman:" by Dr. George H Napheys
Quadruplets were born in Des Moines, Iowa.
"Invasion" by William Fitzgerald Jenkins
I mean to say 'The Heavenly Quadruplets' doesn't sound nearly so neat as 'The Heavenly Twins.
"Changing Winds" by St. John G. Ervine
He reports the case of an epileptic mother who had 36 children, including six twins, four times quadruplets, twice triplets.
"Degeneracy" by Eugene S. Talbot

In news:

Virginia Tech freshman class includes the school's first set of quadruplets.
Many of these children were born preemies with extremely low birth weight – including twins, triplets and quadruplets.
Andrew Ronda, the 16-year old Medford quadruplet charged with stabbing his brother is headed to a Portland mental health facility- Albertin Kerr- for treatment.
A Medford quadruplet charged with attempted murder for stabbing his brother will now be placed under the care of juvenile court.
New Orleans doctors deliver triplet boys, quadruplet girls within 24 hours.
Doctors at Ochsner Medical Center delivered triplet boys and quadruplet girls within 24 hours.
Vanessa Menjivar, the mother of the Bowling Green Quadruplets has a serious disease called Guilliane Barre.
Quadruplets whose mother died after childbirth — from left, Theo, Willy, Stella and Idda — live at the Berega Orphanage.
Naples residents Sheri Green, left, and Laura Cavin, gather their four 1-year-old quadruplets, Anthony, Derrick, Brianna and Cason, at the end of the infants' first trip to the beach on Wednesday, April, 2, 2012, at Lowdermilk Park in Naples.
Local same-sex couple bears the responsibility of quadruplets together.
Quadrupletes on the first day of school.
A 35-year-old Canadian woman has given birth to rare identical quadruplets, hospital officials said.
Quadruplets in beef cattle are even rarer than the one in 665,000 quad births for dairy cows.
Quadruplets in beef cattle are even rarer than the one in 665,000 quad births for dairy cows JOHN STENNES FORUM COMMUNICATIONS CO.

In science:

The ground state of this trio of spins S = 3/2 is a degenerate quadruplet.
Spin-3/2 random quantum antiferromagnetic chains
By definition, the quadruplet [ai−1 , di−1 , ci , ai ] is the list of B-coefficients of gi on the subinterval Ii .
Generalized $C^1$ quadratic B-splines generated by Merrien subdivision algorithm and some applications
For M2 , which is related to the shot noise, the contributing tra jectory quadruplets can be formed by cutting periodic orbits twice , and this approach has been generalised in the complementary work of Ref. .
Universality in chaotic quantum transport: The concordance between random matrix and semiclassical theories
In this case, the quadruplet (φ, η , ξ , G) is called an almost paracontact metric Finsler structure and E is called an almost paracontact metric Finsler vector bundle.
Almost Paracontact Finsler Structures on Vector Bundle
In order to simultaneously address the four lines in one quadruplet without affecting the other two quadruplets, the envelope of the RF pulses was Gaussian shaped and the RF power was adjusted to obtain pulses of ≈ 300µs.
Experimental Quantum Computation with Nuclear Spins in Liquid Solution