optimality
The property of being optimal.

optimation
optimization.

optimations
plural of optimation

optimedin
A particular olfactomedin

optimism
a tendency to expect the best, or at least, a favourable outcome
the doctrine that this world is the best of all possible worlds
the belief that good will eventually triumph over evil

optimisms
plural of optimism

optimity
The state of being best.

optionalities
plural of optionality

optionality
The value of additional optional investment opportunities available only after having made an initial investment.
Quality or state in which choice or discretion is allowed.

optionalization
The process of making something optional.

optioneering
in-depth consideration of various alternatives to find the best or preferred option

optioner
Alternative form of optionor.

optionlessness
Absence of options.

optoacoustics
optoacoustic interactions generally

optobiology
optica biology

optoejection
optical ejection

optoisolation
isolation of part of an electrical circuit by means of an optoisolator

optokinesis
The movement of the eye in response to an external stimulus

optology
The study of sight.

optomagnonics
The study of optical magnons

optomechatronics
The integration of optical components and technology into mechatronic systems.

optometry
The art and science of vision and eye care.

optophobia
The fear of opening one's eyes.

optophysiology
The physiology of the action of light
The physiology of vision

optoporation
Synonym of photoporation.

optoporations
plural of optoporation

optospintronics
The (study of the) interaction of light with spin polarization (spintronics)

optostimulation
optical stimulation

optostimulations
plural of optostimulation

opulence
Wealth.
Abundance, bounty, profusion.
Ostentatious display of wealth and luxury; plushness.

opulences
plural of opulence

opulencies
plural of opulency

opulency
Archaic form of opulence.

opuscle
Obsolete form of opuscule.

opuscles
plural of opuscle

opuscula
plural of opusculum

opuscule
A small or petty work.

opuscules
plural of opuscule

opusculum
An opuscule; a short work.

oracularities
plural of oracularity

oracularity
Oracular speech or behaviour.

oracularness
oracularity

oraculousness
The state or condition of being oraculous.

oralisation
The act or an act of oralising; the act or an act of turning something written into something oral.

oralisations
plural of oralisation

oralism
A philosophy of education for the deaf, opposed to manualism, that uses spoken language consisting of lipreading, speech, the process of watching mouth movements, and mastering breathing techniques.

oralisms
plural of oralism

oralities
plural of orality

orality
The state of being oral.

oralization
The act or an act of oralizing; the act or an act of turning something written into something oral.

oralizations
plural of oralization

oralness
The quality or condition of being oral.

orangeness
The quality of being orange in colour.

orangeyness
Alternative spelling of oranginess.

oranginess
The quality or state of being orangey, as:
The quality or state of being orangey, as:

orangishness
The quality or state of being orangish: somewhat orange, orange-like, or somewhat like an orange.

orans
A figure in an attitude of prayer, usually standing, with the elbows close to the sides of the body and with the hands outstretched sideways, palms up.
The posture or bodily attitude of such a figure.

orant
Alternative form of orans.

oranta
Alternative form of orans.

orante
Alternative form of orans.

orantes
plural of orans

orants
plural of orant

oratories
plural of oratory

oratorship
The role or status of an orator.

oratory
A private chapel or prayer room.
A Roman Catholic chapel; a building for public or private worship that is not a parish church.
A Catholic church belonging to the Oratory of Saint Philip Neri.

orbation
The state of being orbate, or deprived of parents or children; privation, in general; bereavement.

orbicle
A small orb or sphere.

orbicles
plural of orbicle

orbicularity
The quality of being orbicular.

orbiculation
The state or quality of being orbiculate.

orbiform
A plane for which the distance between the points of contact of two nonequal parallel tangents at a circle is the same everywhere.

orbispace
A topological space or generalization of an orbifold.

orbispaces
plural of orbispace

orbiton
A quasiparticle, corresponding to the orbital energy of an electron, which can result from an electron apparently ‘splitting’ under certain conditions.

orbitons
plural of orbiton

orbitotomies
plural of orbitotomy

orbitotomy
incision into the orbit of the eye

orbitude
bereavement or loss of parents or children

orblet
A small orb.

orblets
plural of orblet

orchesographies
plural of orchesography

orchesography
An enhanced form of choreography that includes details of the music to accompany the dance

orchestics
The art of dance

orchestra
A large group of musicians who play together on various instruments, usually including some from strings, woodwind, brass and/or percussion; the instruments played by such a group.
A semicircular space in front of the stage used by the chorus in Ancient Greek and Hellenistic theatres.
The area in a theatre or concert hall where the musicians sit, immediately in front of and below the stage, sometimes (also) used by other performers.

orchidelirium
Synonym of orchidomania.

orchideology
Alternative form of orchidology.

orchidology
The study of orchids.

orchidomania
An obsession with orchids; enthusiasm for raising or collecting orchids, especially in the Victorian era.

orchidometry
The measurement of the volume of the testicles

orchidotomies
plural of orchidotomy

orchidotomy
surgical removal of the testicles; castration

orchidynia
Alternative form of orchiodynia.

orchiodynia
pain in the testicles

orchiotomy
Synonym of orchidotomy.

orchitogenicity
The condition of being orchitogenic

orchotomies
plural of orchotomy

orchotomy
The surgical removal of a testicle; castration.

orcishness
The quality of being orcish.

orckind
All orcs, considered as a group.

orcos
Use of an oath to enhance the believability of a statement.

orda
A political and military organizational structure used by Turkic and Mongol peoples, sometimes referred to as a horde.

ordainment
ordination

ordainments
plural of ordainment

ordalium
Trial by ordeal.

ordas
plural of orda