opisthobranch
A gastropod with gills behind the heart, formerly thought to belong to a single group.

opisthobranchs
plural of opisthobranch

opisthocline
leaning backwards

opisthoclines
plural of opisthocline

opisthocoelian
opisthocoelous

opisthocoelous
concave behind; applied especially to vertebrae in which the anterior end of the centrum is convex and the posterior concave

opisthocomine
Of or pertaining to birds of the family Opisthocomidae, which is represented by the sole extant genus Opisthocomus and species Opisthocomus hoazin (hoazin).

opisthodelphic
Having parallel uteri that are directed to the rear

opisthogastric
behind the stomach

opisthoglyphous
Whose teeth include an enlarged pair at the back of the maxillae which normally angle backwards and are grooved to channel venom into the puncture.

opisthognathous
Having retreating jaws or teeth.

opisthographic
Written on both sides.
Relating to an opisthograph.

opisthogyrate
That curves toward the posterior

opisthomonorchiine
Of or relating to the monorchiids of genus Opisthomonorchis

opisthonotal
opisthosomal and dorsal

opisthopubic
Having the pubis bones pointing backward, as in some dinosaurs.

opisthorchidal
Relating to the opisthorchids

opisthorhynchous
Having the beak directed backwards.

opisthosomal
Relating to the opisthosoma.

opisthosomatic
Alternative form of opisthosomal.

opisthothoracic
Relating to an opisthothorax.

opisthotonic
Relating to opisthotonus.

opiumlike
Resembling or characteristic of opium.

oplan
operational plan

oplax
Pertaining to the dual of a lax monoidal functor.

opless
Without ops (channel operators).

opmonoidal
Having a natural family of distributive morphisms and an identity morphism that are coherent.

opotherapeutic
of or relating to opotherapy

oppidan
Of or pertaining to a town or conurbation.

oppies
plural of oppie

opportune
Suitable for some particular purpose.
At a convenient or advantageous time.

opportuneless
Devoid of opportunity.

opportuning
opportunistic

opportunistic
Taking advantage of situations that arise.
Taking advantage of situations to advance one's own interests without regard for moral principles.

opportunityless
Devoid of opportunity.

opposable
Susceptible to being opposed or resisted.
Capable of being placed opposite something else.

opposed
Acting in opposition; opposing.
Being, of having an opponent; not unopposed.
Opposite.

opposeless
Not to be effectually opposed; irresistible.

oppositiflorous
Having opposite peduncles.

oppositifolious
Placed at the same node with a leaf, but separated from it by the whole diameter of the stem.

oppositional
Of, pertaining to, or exhibiting opposition.

oppositionary
oppositional

oppositionless
without opposition

oppositious
Characterized by, or relating to, opposition; opposing.

oppositipetalous
Facing a petal.

oppositisepalous
Facing a sepal.

oppositive
Expressing contrariety.

oppositives
plural of oppositive

oppressible
Able to be oppressed.

oppressional
Exhibiting or relating to oppression.

oppressionist
Taking part in or promoting oppression.

opprobrious
Causing opprobrium; offensive and shameful.

oppugnant
opposing, antagonistic, contrary

oppy
Characteristic of an opp; inimical, hostile.

opsiblastic
Exhibiting a period of dormancy before starting to develop.

opsimathic
Of or pertaining to an opsimath.
Of or pertaining to opsimathy.

opsimathy
Learning or education that occurs late in life.

opsonic
Relating to, produced by, or involving opsonin.

opsoniferous
Bearing opsonin.

opsonizable
Able to be opsonized.

opsonophagocytic
Related to opsonophagocytosis

opsonophagocytosed
infected with opsonophagocytosis

opsonophagocytotic
Relating to opsonophagocytosis.

opsonophilic
Relating to opsonophilia.

opthalmic
Misspelling of ophthalmic.

optical
Of or relating to sight; visual.
Designed to assist or enhance sight
Of or relating to optics.
Of or relating to visible light.
Incorporating light-sensitive devices.

opticals
plural of optical

opticochemical
Relating to the chemistry of the eye.

opticokinetic
optokinetic

opticopneumatic
Having both optic and pneumatic elements

opticospinal
Of, pertaining to, or affecting the optic nerve and the spinal cord

optimal
The best, most favourable or desirable, especially under some restriction.

optimals
plural of optimal

optimific
producing the optimum outcome

optimisable
Alternative spelling of optimizable.

optimistic
Expecting the best in all possible ways.
Allowing other processes to perform transactions on the same data at the same time, and checking for conflicts only when changes need to be written back.

optimistical
optimistic

optimizable
Capable of being optimized.

optimizational
Relating to optimization

optimum
The best or most favorable condition, or the greatest amount or degree possible under specific sets of comparable circumstances.
Any long period of time marked by a persistently warm climate; a climatic optimum.

optionable
Of or pertaining to options on a stock or equity. For some stocks, it is possible to trade options on them, hence they are optionable, for other stocks options aren't traded so they are not optionable.

optional
Not compulsory; left to personal choice; elective.

optionals
plural of optional

optionary
optional

optioned
simple past and past participle of option

optionless
Without an option.

optionlike
Resembling or characteristic of an option.

optoacoustic
Describing any of several interactions between light and sound

optobionic
optically bionic

optocapillary
Relating to the interaction of light on capillary effects

optochemical
Relating to the chemical processes involved in sight or vision

optochiasmatic
Relating to the optic chiasm.

optociliary
retinochoroidal

optocinetic
Misspelling of optokinetic.

optocollic
Relating to the eye and the neck, but especially to the avian reflex that holds the head steady during flight

optocoupled
coupled by means of an optocoupler

optodynamic
Of or pertaining to optodynamics

optoelectric
Of or pertaining to the conversion of light energy into electricity

optoelectrical
Alternative form of optoelectric.

optoelectroactive
optically electroactive

optoelectromechanical
optoelectric and electromechanical

optoelectronic
Of or pertaining to optoelectronics.
That has both optical and electronic components, especially such components that interact.

optoepigenetic
Whose epigenetic activity is modulated by light

optofluidic
Of or pertaining to optofluidics

optogalvanic
Describing any effect of light upon the electrical conductivity of a material

optogenetic
generated by light
Describing any of several techniques in which optical technology is used to form images of genetically targeted proteins or neurons

optogenetical
Alternative form of optogenetic.

optoisolated
isolated by means of an optoisolator

optokinetic
Of or pertaining to movement of the eyes

optological
Of or relating to optology.

optomagnetic
optical and magnetic; related to optomagnetism

optomagnonic
Relating to optical magnons or to optomagnonics

optomechanical
Of or pertaining to optomechanics

optomechatronic
Of or relating to optomechatronics.

optometric
Of or pertaining to optometry

optometrical
Of or pertaining to optometry.

optomotor
Describing movement of the eye, head or body (especially of insects) that steadies the field of vision

optophysiologic
Alternative form of optophysiological.

optophysiological
Relating to optophysiology

optoplasmonic
optical and plasmonic

optospectroscopic
Relating to optical spectroscopy

optospintronic
Related to optospintronics

optotagged
simple past and past participle of optotag

optothermal
Relating to light and heat

optotypic
Relating to an optotype

optronic
optoelectronic

opulent
Luxuriant, and ostentatiously magnificent.
Rich, sumptuous and extravagant.

opuscular
Of or relating to an opusculum.