overrefinement vs. straining

overrefinement vs. twisting

overrefinement vs. torture

offer vs. pass

offer vs. offering

offer vs. propose

offer vs. proffer

offer vs. provide

offer vs. volunteer

ownership vs. possession

oscitance vs. yawn

oscitance vs. oscitancy

oscitancy vs. yawn

onanism vs. withdrawal

observance vs. observation

observation vs. watching

observation vs. sighting

observation vs. reflection

observation vs. reflexion

outlook vs. prospect

orientation vs. preference

orientation vs. predilection

overproduction vs. overrun

output vs. yield

output vs. turnout

output vs. production

overuse vs. overutilization

overuse vs. overutilisation

overexploitation vs. overuse

overdrive vs. overuse

onset vs. onslaught

onrush vs. onslaught

order vs. ordering

order vs. rescript

order vs. society

order vs. orderliness

order vs. place

order vs. put

order vs. say

order vs. tell

order vs. prescribe

order vs. ordinate

ordain vs. order

order vs. regulate

order vs. regularize

order vs. regularise

objection vs. protest

objection vs. remonstrance

objection vs. remonstration

oblation vs. offering

obviation vs. preclusion

outlay vs. spending

obedience vs. respect

obedience vs. obeisance

opinion vs. ruling

opinion vs. view

oversimplification vs. simplism

outlet vs. release

offspring vs. young

ophidian vs. snake

oldwench vs. oldwife

opossum vs. possum

opossum vs. phalanger

onychophoran vs. peripatus

onager vs. trebuchet

onager vs. trebucket

omasum vs. psalterium

oryx vs. pasang

orang vs. orangutan

orangutan vs. orangutang

oarfish vs. ribbonfish

ointment vs. salve

oddity vs. queerness

oddity vs. oddness

ottoman vs. puff

overcoat vs. overcoating

outfit vs. turnout

ornithopter vs. orthopter

obstructer vs. obstructor

obstructor vs. resister

obstructionist vs. obstructor

oscilloscope vs. scope

opener vs. undoer

opener vs. unfastener

opener vs. untier

oeuvre vs. work

OR vs. surgery

outerwear vs. overclothes

outhouse vs. privy

outpost vs. outstation

outturn vs. turnout

oracle vs. prophet

oracle vs. prophesier

oracle vs. seer

organdie vs. organdy

oilskin vs. slicker

orphanage vs. orphanhood

overprint vs. surprint

ovolo vs. thumb

overlay vs. overlayer

overlay vs. sheathing

overlay vs. overlie

overburden vs. overload

overcharge vs. overload

overload vs. surcharge

organiser vs. organizer

oarlock vs. pin

orbiter vs. satellite

offset vs. runner

otherworldliness vs. spirituality

obsessiveness vs. obsessivity

openness vs. receptiveness

ocellus vs. stemma

opacity vs. opaqueness

ornateness vs. rhetoric

obviousness vs. patency

opportuneness vs. patness

opportuneness vs. timeliness

oneness vs. unity

odiousness vs. offensiveness

outlandishness vs. weirdness

obscureness vs. obscurity

obscureness vs. reconditeness

obscureness vs. unimportance

objectiveness vs. objectivity

oiliness vs. unction

oiliness vs. oleaginousness

oleaginousness vs. unction

obstinacy vs. obstinance

obstinance vs. stubbornness

obsoleteness vs. superannuation

obsequiousness vs. servility

obsequiousness vs. subservience

odor vs. smell

odour vs. smell

oblongness vs. rectangularity

orthogonality vs. perpendicularity

orbit vs. reach

orb vs. orbit

orbit vs. revolve

overabundance vs. surfeit

oversupply vs. surfeit

overplus vs. plethora

overplus vs. superfluity

ossicle vs. ossiculum

oligodendria vs. oligodendroglia

outgrowth vs. process

olfaction vs. smell

oblivion vs. obliviousness

overtone vs. partial

overestimation vs. overvaluation

overestimate vs. overvaluation

overappraisal vs. overvaluation

overestimation vs. overrating

overestimation vs. overreckoning

oneirism vs. reverie

overestimate vs. overestimation

overestimate vs. overrate

overestimate vs. overvalue

outline vs. schema

outline vs. scheme

outline vs. sketch

orthodontia vs. orthodontics

orthodontics vs. orthodonture

otorhinolaryngology vs. rhinolaryngology

otolaryngology vs. rhinolaryngology

orthopaedics vs. orthopedics

orography vs. orology

oceanography vs. oceanology

orthoepy vs. pronunciation

obeah vs. obi

offprint vs. separate

oath vs. swearing

oath vs. swearword

obloquy vs. opprobrium

overbid vs. overcall

obbligato vs. obligato

opus vs. piece

overture vs. preliminary

octet vs. octette

outcry vs. outshout

orison vs. prayer

outcome vs. termination

omen vs. prognostic

oscillation vs. vibration

oink vs. squeal

overspill vs. runoff

ooze vs. transude

ooze vs. seep

outflow vs. spring

omelet vs. omelette

ovalbumin vs. white

oddments vs. ragbag

outback vs. remote

orient vs. tailor

orient vs. orientate

orient vs. point

outcrop vs. outcropping