underwool
The short, wooly underfur of certain animals, especially sheep.

underwools
plural of underwool

unga
Sarotherodon linnellii, a cichlid endemic to Lake Barombi Mbo in western Cameroon.

ungas
plural of unga

unguiculi
plural of unguiculus

unguiculus
A diminutive claw or similar appendage at the end of an insect's foot.

ungulates
plural of ungulate

unicell
Any unicelled organism.

unicells
plural of unicell

unicorn fish
Alternative form of unicornfish.

unicornfish
Any fish of genus Naso.
A unicorn crestfish (Eumecichthys fiski).
Any fish of genus Coelorinchus, including the unicorn grenadier.
A scrawled filefish (Aluterus scriptus).

unicornfishes
plural of unicornfish

unificationists
plural of unificationist

unigenesis
Synonym of parthenogenesis.

unionids
plural of unionid

unionoids
plural of unionoid

uniramian
Any member of the Uniramia, a group of arthropods.

uniramians
plural of uniramian

unke
The European fire-bellied toad (Bombina bombina).

unkenreflex
A defensive posture adopted by several branches of the amphibian class, including, but not exclusive to, salamanders, toads, and certain species of frogs.

untouchables
plural of untouchable

upeygan
A borele or two-horned black rhinoceros (Diceros bicornis).

upflight
upward flight, typically of an insect

upflights
plural of upflight

upla
Alternative form of oopla.

upogebiid
Any member of the Upogebiidae.

upogebiids
plural of upogebiid

uppercruster
A member of the upper crust; a social elite.

uppercrusters
plural of uppercruster

upperpart
Any of the upper parts of a bird, including the mantle, back, rump and upper part of the tail coverts

upperparts
plural of upperpart

uppertail
The dorsal part of the tail of a bird

uppertails
plural of uppertail

upperwing
The upper part of a wing of a bird or butterfly

upperwings
plural of upperwing

upside-down catfish
Any of various freshwater catfish that swim upside-down, such as Synodontis decorus, Synodontis multipunctatus, and especially Synodontis nigriventris

upupid
Any member of the family Upupidae, the hoopoes.

upupids
plural of upupid

uraeotyphlid
Any caecilian in the family Uraeotyphlidae, now considered to be part of the Ichthyophiidae.

uraeotyphlids
plural of uraeotyphlid

uranid
Alternative form of uraniid.

uranids
plural of uranid

uraniid
Any of the family Uraniidae, swallowtail moths.

uraniids
plural of uraniid

urceolarian
Any member of the Urceolaria.

urceolarians
plural of urceolarian

ureaplasma
Any member of the genus Ureaplasma of urease-positive bacteria

ureaplasmas
plural of ureaplasma

ureogenesis
The biosynthesis of urea

urinomics
The identification of the totality of the constituents of the urine of an organism

urmetazoan
The hypothetical common ancestor of all animals

urmetazoans
plural of urmetazoan

uroboroi
plural of uroboros

uroboros
Alternative spelling of ouroboros.

uroboroses
plural of uroboros

urodelan
Any member of the order Urodela (syn. of Caudata); a salamander.

urodelans
plural of urodelan

urodele
Any caudate amphibian.

urodelians
plural of urodelian

urodermal
Either of a pair of thin dermal bones, derived from scales, at the rear of the caudal fin of some fish

urodermals
plural of urodermal

urogram
An image of the urinary tract, taken by X-ray.

urograms
plural of urogram

uroneural
Synonym of urodermal.

uroneurals
plural of uroneural

uropeltid
Any member of the family Uropeltidae of shield-tail snakes.

uropeltids
plural of uropeltid

uropeltoid
Any member of the Uropeltoidea superfamily of snakes.

uropeltoids
plural of uropeltoid

urophysis
A neurohaemal organ of the caudal neurosecretory system of teleost fish

uropod
either of the two posterior abdominal appendages of the lobster, shrimp and some other crustaceans.
the hind part of polarized leukocytes, mostly involved in cell-to-cell interaction, cell activation and apoptosis.

uropodoids
plural of uropodoid

uropods
plural of uropod

uropygia
plural of uropygium

uropygium
The posterior part of a bird's body from which the tailfeathers grow.

urostealiths
plural of urostealith

ursid
Any species of the family Ursidae; a bear, a giant panda, or any of certain extinct relatives.

ursids
plural of ursid

urson
A species of New World porcupine, Erethizon dorsatum.

ursons
plural of urson

ursusagalmatophilia
The sexual or romantic attraction to teddy bears; a fetish or paraphilia for stuffed animal bears.

urutu
A venomous pit viper of species Bothrops alternatus.

urutus
plural of urutu

usance
The length of time permitted for the payment of a bill of exchange.
Use.
Customary or habitual usage.
The interest paid on a borrowed sum, usury.

usances
plural of usance

usaunce
Obsolete form of usance.

usaunces
plural of usaunce

usie
A selfie of a group of people.

usies
plural of usie

ussie
A photographic group portrait, especially one taken manually (not using a timer, tripod etc.) with a small camera or mobile phone by a member of the group.

ussies
plural of ussie

ussuritid
Any of the extinct ammonites in the family Ussuritidae.

ussuritids
plural of ussuritid

uta
cutaneous leishmaniasis

utas
The octave, or seventh day after a festival (i.e., the eighth day counting inclusively, in the ancient Roman way).

uterosalpingogram
A hysterosalpingogram.

uterosalpingograms
plural of uterosalpingogram

utias
plural of utia

utis
Alternative form of utas.

utricle
A small cell, sac, or bladder-like protuberance in an animal or plant:
A small cell, sac, or bladder-like protuberance in an animal or plant:
A small cell, sac, or bladder-like protuberance in an animal or plant:

utricles
plural of utricle

uturuncu
A jaguar.

uturuncus
plural of uturuncu

uveovortex
A uveal vortex

vaccinogen
An animal that is a source of a vaccine

vaccinogens
plural of vaccinogen

vacuome
The vacuoles and vacuolar system of an organism

vacuomes
plural of vacuome

vaejovid
Any scorpion in the family Vaejovidae

vaejovids
plural of vaejovid

vahlkampfiid
Any member of the family Vahlkampfiidae of protozoans.

vahlkampfiids
plural of vahlkampfiid

vairone
Any of several fish of the genus Telestes native to Europe.

vairones
plural of vairone

valencia
A kind of woven fabric for waistcoats, having the weft of wool and the warp of silk or cotton.

valencias
plural of valencia

vallicula
Alternative form of vallecula.

valliculae
plural of vallicula

vallum
A rampart; a wall, as in a fortification.
The eyebrow.

vallums
plural of vallum

valraven
Alternative form of valravn.

valravens
plural of valraven

valravn
A supernatural raven in Danish folklore and in fiction, often said to be able to shapeshift into a knight.

valravns
plural of valravn

valvatidan
Any starfish of the order Valvatida

valvatidans
plural of valvatidan

valvifer
Any of the basal plates of an insect's ovipositor that arise from the eighth and ninth abdominal segments

valvifers
plural of valvifer

vampling
A newly-turned or fledgling vampire.
A contemptible or insignificant vampire.

vampyromorph
A cephalopod belonging to the taxonomic order Vampyromorphida, of which the vampire squid is the only surviving species.

vampyromorphid
Any member of the Vampyromorphida order of cephalopods.

vampyromorphids
plural of vampyromorphid

vampyromorphs
plural of vampyromorph

vampyropod
A member of the proposed group Vampyropoda (equivalent to the superorder Octopodiformes), comprising vampire squid and octopuses; an octopodiform.

vampyropods
plural of vampyropod

vampyroteuthid
Any member of the family Vampyroteuthidae. the vampire squids.

vampyroteuthids
plural of vampyroteuthid

vanadylates
plural of vanadylate

varan
The monitor lizard.

varanid
Any lizard of the genus Varanus; a monitor lizard.

varanids
plural of varanid

varaniform
Any varanid or similar creature

varaniforms
plural of varaniform

varanines
plural of varanine

varanoid
Any member of the superfamily Varanoidea of lizards, including the well-known Australian family Varanidae (the goannas).