olive sea snake
A venomous species of sea snake, Aipysurus laevis.

oliveback
Any of the birds in the genus Nesocharis or Delacourella, found in western and central Africa.

olivebacks
plural of oliveback

ollama
Alternative spelling of ulama.

ollinelid
Any trilobite of the family Olenellidae.

oma
Grandmother, grandma.

omalogyrid
Any member of the Omalogyridae.

omalogyrids
plural of omalogyrid

omas
plural of oma

ome
The totality of a certain type of biological entity in an organism etc., e.g. the genome or proteome.

omena
In Kenya, small fish dried and milled into flour.

omes
plural of ome

ommastrephid
Any squid in the family Ommastrephidae.

ommastrephids
plural of ommastrephid

omnibenthivore
Any benthic omnivore

omnibenthivores
plural of omnibenthivore

omnicarnivore
An animal that eats many types of other animal

omnicarnivores
plural of omnicarnivore

omniherbivore
An animal that eats many types of plant.

omniherbivores
plural of omniherbivore

omnivory
The consumption of both animal and plant matter, or of material from multiple trophic levels; the act or condition of being omnivorous.

omomyid
Any member of the family †Omomyidae, a diverse group of extinct primates.

omomyids
plural of omomyid

omomyiform
Any primate of the infraorder Omomyiformes

omomyiforms
plural of omomyiform

omosudid
Any fish in the family Omosudidae, which consists of a single known species, the deep-sea hammerjaw (Omosudis lowii).

omosudids
plural of omosudid

omphaloliths
plural of omphalolith

onaga
Longtail snapper (Etelis coruscans), a species of ray-finned fish.

onagga
The dauw.

onaggas
plural of onagga

onbeia
An elephant's tusk trumpet.

onbeias
plural of onbeia

onchidiid
Any slug in the family Onchidiidae.

onchidiids
plural of onchidiid

oncogenome
A genome of oncogenes.

oncogenomes
plural of oncogenome

oncomiracidia
plural of oncomiracidium

oncomiracidium
The free-swimming, ciliated larval form of a monogenean.

oncoproteogenome
A proteogenome of oncogenes.

oncoproteogenomes
plural of oncoproteogenome

onera
plural of onus

onespot fringehead
Neoclinus uninotatus, a species of fringehead blenny.

onikulactone
A cat attractant found in Boschniakia rossica.

oniscoid
A member of the Oniscoidea; a woodlouse.

oniscoids
plural of oniscoid

onocentaur
A centaur with the body of an ass, instead of a prototypical horse.

onocentaurs
plural of onocentaur

onoi
plural of onos

onolatries
plural of onolatry

onolatry
Worship of the ass or donkey.
Preoccupation with or devotion to something foolish.

onomatophore
A specimen that serves to bear a taxonomic name, as a type.

onomatophores
plural of onomatophore

onos
Synonym of epinetron (“Attic pottery item”).

onotherapy
Donkey riding as physical therapy.

ontogeneses
plural of ontogenesis

ontogenesis
The generation and development of an individual organism from fertilization to adulthood.

ontogenies
plural of ontogeny

ontogeny
Synonym of ontogenesis.

onus
A legal obligation.
Burden of proof, onus probandi.
Stigma.
Blame.
Responsibility; burden.

onuses
plural of onus

onychophoran
Any of many wormlike carnivorous ecdysozoan animals of the phylum Onychophora.

onychophorans
plural of onychophoran

onychopod
Any branchiopod crustacean of the suborder Onychopoda

onychopods
plural of onychopod

onychoteuthid
Any squid in the family Onychoteuthidae.

onychoteuthids
plural of onychoteuthid

onyxes
plural of onyx

ooaa
Any member of the extinct species †Moho braccatus of oo birds of Hawaii.

oobit
A caterpillar.

oobits
plural of oobit

oocytogenesis
The creation and development of oocytes

ooecia
plural of ooecium

ooecium
An ovicell of a bryozoan.

oogram
An image, typically of parasite eggs, produced by oography

oograms
plural of oogram

ookinete
The motile zygote of a parasite of the malaria mosquito that forms an oocyst in the mosquito's gut

ookinetes
plural of ookinete

ookpik
A handicraft stuffed toy owl, often made from wolf fur, sealskin, or similar materials.

ookpiks
plural of ookpik

oolachan
Alternative form of eulachon.

oolachans
plural of oolachan

oolachen
Alternative form of eulachon.

oolachens
plural of oolachen

oolakan
Alternative form of eulachon.

oolakans
plural of oolakan

oolican
Alternative form of eulachon.

oolicans
plural of oolican

oolichan
Alternative form of eulachon.

oolichans
plural of oolichan

oont
A camel.

oonts
plural of oont

oophagy
The cannibalization of subordinate eggs within a homogeneous population or the uterus; particularly as it relates to certain insect and aquatic species.

oopla
Dried cow dung formed into cakes for use as fuel.

ooplah
Alternative form of oopla.

oopuhue
globefish

oosome
A mass of protoplasm at one end of an insect egg

oosomes
plural of oosome

oosorption
The resorption of a developing egg typically as a response to a parasite

oosorptions
plural of oosorption

oozel
Alternative form of ouzel.

oozels
plural of oozel

oozooid
A zooid that develops from an egg and reproduces by budding

opah
Any of various large, colourful, deep-bodied pelagic fish of the family Lamprididae.

opahs
plural of opah

opaleye
A fish, Girella nigricans, a species of sea chub found in the Eastern Pacific.

opaleyes
plural of opaleye

opalfish
Hemerocoetes monopterygius, a ray-finned fish, found only around New Zealand.

opercle
An operculum.

opercles
plural of opercle

opercula
plural of operculum

opercule
Alternative form of operculum.

opercules
plural of opercule

operculum
A covering flap in animals, such as a gill cover.
The lidlike portion of a moss sporangium or of a fruit that detaches to allow the dispersal of spores or seeds.
A gum flap covering (part of) a partially erupted tooth, usually a wisdom tooth.
A structure which serves as a cover or lid.
One of several flaps of cerebral cortex covering the insula.

operculums
plural of operculum

ophiacodont
Any member of the Ophiacodontidae family of Carboniferous and Permian vertebrates

ophiacodonts
plural of ophiacodont

ophiceratid
Any member of the family †Ophiceratidae of extinct ammonite cephalopods.

ophiceratids
plural of ophiceratid

ophichthid
Any eel in the family Ophichthidae.

ophichthids
plural of ophichthid

ophidiasterid
Any starfish in the family Ophidiasteridae.

ophidiasterids
plural of ophidiasterid

ophidiiforms
plural of ophidiiform

ophiolatry
snake worship

ophiophage
Any animal that eats snakes.

ophiophages
plural of ophiophage

ophioplutei
plural of ophiopluteus

ophiopluteus
A free-swimming larval stage of some brittle stars, having four pairs of rigid arms lined with cilia.

ophistokont
Misspelling of opisthokont.

ophiurans
plural of ophiuran

ophthalmomyiasis
Myiasis of the eye.

opinici
plural of opinicus

opinicus
A heraldic imaginary creature with an eagle's head, a short tail, and sometimes wings.

opisthoglyph
Any opisthoglyphous snake.

opisthoglyphs
plural of opisthoglyph

opisthokont
Any of very many eukaryotes, including animals and fungi, whose flagellate cells (if any) propel themselves with a single posterior flagellum.

opisthokonts
plural of opisthokont

opisthomerite
The posterior gonopods of a millipede of the infraclass Helminthomorpha

opisthomerites
plural of opisthomerite

opisthoparian
Any trilobite of the order †Opisthoparia.

opisthothele
Any spider of the suborder Opisthothelae.

opistokont
Misspelling of opisthokont.

oplurid
Any lizard in the family Opluridae.

oplurids
plural of oplurid

oppeliid
Any member of the Oppeliidae.

oppeliids
plural of oppeliid

oprichnik
A member of the bodyguard corps established by Tsar Ivan the Terrible to govern a division of Russia from 1565 to 1572.

oprichniks
plural of oprichnik

opticalman
A member of the navy who specialized in the use of optical tools.

opticalmen
plural of opticalman

optimate
A member of the patrician ruling class in republican Ancient Rome; an aristocrat, a noble.

optimates
plural of optimate

ora
plural of os (“anatomical opening”)