onomasticon
A book, list, or vocabulary of names, especially of people.

onomasticons
plural of onomasticon

onomasts
plural of onomast

onomatoclast
An opponent of onomatodoxy.

onomatoclasts
plural of onomatoclast

onomatologist
onomastician

onomatologists
plural of onomatologist

onsetter
A worker at the bottom of a mineshaft who exchanges the empty and full corves.

onsetters
plural of onsetter

ontogeneticist
A geneticist whose speciality is ontogenesis

ontogeneticists
plural of ontogeneticist

ontogenist
One who studies ontogeny.

ontogenists
plural of ontogenist

ontologist
A scholar or theorist of ontology, or an adherent of a particular ontological doctrine.

ontologists
plural of ontologist

ontotheologian
One who studies ontotheology.

ontotheologians
plural of ontotheologian

ontotheologist
One who studies ontotheology.

ontotheologists
plural of ontotheologist

onychomancy
An ancient form of divination based on the symbols that are reflected by sunlight on a person's fingernails.

onychophagist
A person who bites his or her fingernails.

onychophagists
plural of onychophagist

oogle
A hobo or transient who is homeless by choice rather than necessity.

oogles
plural of oogle

ooher
One who oohs (in various senses).

oologist
a person who studies or specializes in oology

oologists
plural of oologist

oopart
An object found in a very unusual or apparently impossible archaeological context (like the Coso sparkplug found in an allegedly 500,000-year-old geode) which would challenge conventional historiography and chronology if authentic.

ooparts
plural of oopart

opara
The oldest son, who has inherited the rights and responsibilities of his father after his father has died.

openers
plural of opener

opensider
openside flanker

opensiders
plural of opensider

operagoer
Someone who attends an opera performance

operagoers
plural of operagoer

operaphile
One who enthusiastically enjoys opera.

operaphiles
plural of operaphile

operaphobe
A person who hates opera.

operaphobes
plural of operaphobe

operatee
Someone who has an operation.

operatees
plural of operatee

operationalist
A proponent of operationalism.

operationalists
plural of operationalist

operationist
A proponent of operationism.

operationists
plural of operationist

operatist
A composer of opera.

operatists
plural of operatist

operator
A person or organisation that operates a device, system, service, etc.
A telecommunications facilitator whose job is to connect or otherwise assist callers.
A member of a military special operations unit.
The game of Chinese whispers.
A person who is adept at making deals or getting results, especially one who uses questionable methods.
A function or other mapping that carries values defined on a domain into another value or set of values in a defined range.
The administrator of a channel or network on IRC.
A symbol that represents a construct in a programming language and differs from a normal function in its syntax.
A kind of expression that enters into an a-bar movement dependency and is said to bind a variable.
A bus driver.
The company that operates a mine; often the same one that owns the mine.
A thief or charlatan.
A major criminal.
Someone who is successful at pursuing women; a player.

operators
plural of operator

operatour
Obsolete form of operator.

operatours
plural of operatour

operatress
A female operator.

operatresses
plural of operatress

operatrix
A female operator.

operatrixes
plural of operatrix

operettist
The composer of an operetta.

operettists
plural of operettist

ophan
A member of an order of wheel-like angels.

ophanim
plural of ophan

ophicleidist
Someone who plays the ophicleide.

ophicleidists
plural of ophicleidist

ophidian
Any species of the suborder Serpentes; a snake or serpent.

ophidians
plural of ophidian

ophidiophobe
An ophiophobe; one who fears snakes.

ophidiophobes
plural of ophidiophobe

ophiolitologist
One who studies ophiolites.

ophiolitologists
plural of ophiolitologist

ophiologist
One who studies ophiology; an expert on snakes.

ophiologists
plural of ophiologist

ophiophile
A person who loves snakes.

ophiophiles
plural of ophiophile

ophiophilist
Synonym of ophiophile (“person who loves snakes”).

ophiophilists
plural of ophiophilist

ophiophobe
One who fears or hates snakes.

ophiophobes
plural of ophiophobe

ophrydeous
Of or relating to the genus Ophrys of bee orchids.

ophthalmist
One skilled in ophthalmology.

opificer
A person who creates or makes something.

opificers
plural of opificer

opilionologist
One who studies the Opiliones or harvestmen.

opilionologists
plural of opilionologist

opinant
One who offers an opinion.

opinants
plural of opinant

opinator
An opinionated person, or someone who holds an opinion.

opinators
plural of opinator

opiner
One who opines.

opiners
plural of opiner

opiniaster
An opinionated person.

opiniasters
plural of opiniaster

opiniator
Someone who is opinionated.

opiniators
plural of opiniator

opinionatist
Obsolete spelling of opinionist.

opinionatists
plural of opinionatist

opinionator
An opinionated person; one given to conjecture.
One who broadcasts opinions about current events online.

opinionators
plural of opinionator

opinionist
One fond of his own notions, or unduly attached to his own opinions.
One whose unusual or heretical belief or opinion contrasts with the dominant view.

opinionists
plural of opinionist

opinionizer
One who opinionizes.

opinionizers
plural of opinionizer

opinionmaker
One who influences the public in their opinions.

opinionmakers
plural of opinionmaker

opiomaniac
An opium addict.

opiomaniacs
plural of opiomaniac

opiophile
A person who enjoys taking opium.

opiophiles
plural of opiophile

opiumist
One who is addicted to opium.

opiumists
plural of opiumist

oporopolist
A seller of fruit.

oppa
An affectionate term of address for an older brother or somewhat older man.
A male idol revered by a younger female fan.

oppah
Alternative form of oppa.

oppahs
plural of oppah

oppari
An impromptu folk song of southern India, traditionally sung by women during a death ceremony in order to memorialize the person who has died.

opparis
plural of oppari

oppas
plural of oppa

oppo
A friend, associate or colleague.

oppoes
plural of oppo

opponents
plural of opponent

opportunist
Someone who takes advantage of any opportunity to advance their own situation, placing expediency above principle.

opportunists
plural of opportunist

opportunivore
A person who subsists on still-edible food that has been or was going to be discarded.
One who will generally eat whatever is available, having a diet that excludes few foods.
A person who actively seeks or takes advantage of opportunities.

opportunivores
plural of opportunivore

oppos
plural of oppo

opposee
One against whom there is opposition; the opposed party.

opposees
plural of opposee

opposer
One who opposes, one who shows opposition.

opposers
plural of opposer

oppositionist
A person who opposes; especially a member of an official opposition

oppositionists
plural of oppositionist

oppressee
A victim of oppression.

oppressees
plural of oppressee

oppressionists
plural of oppressionist

oppressor
Someone who oppresses another or others.

oppressors
plural of oppressor

oppressour
Obsolete form of oppressor.

oppressours
plural of oppressour

oppugnants
plural of oppugnant

oppugner
Someone who oppugns; an opponent.

oppugners
plural of oppugner

opsimath
A person who learns late in life.

opsimaths
plural of opsimath

opsonist
A practitioner of opsonotherapy.

opsonists
plural of opsonist

opsophagoi
plural of opsophagos

opsophagos
A glutton, a gourmand, chiefly one who hogs and eats excessive amounts of fish.

opster
An artist who creates op art.

opsters
plural of opster