ohm's law

o'keeffe

old-maid's bonnet

old man's beard

old wives' tale

o'neill

one one's coattails

on one's guard

﴾͡๏̯͡๏﴿ O'RLY

﴾͡๏̯͡๏﴿ O'RLY?

orphans' asylum

oscar fingal o'flahertie wills wilde

ostwald's theory of indicators

o'toole

our lady's bedstraw

our lady's mild thistle

our lord's candle

pa'anga

paget's disease

painter's colic

pallas's cat

pallas's sandgrouse

pandora's box

parkinson's

parkinson's disease

parkinson's law

parkinson's syndrome

parrot's beak

parrot's bill

parry's penstemon

parry's pinyon

parson's nose

pascal's law

pascal's law of fluid pressures

patriot's day

pawnbroker's shop

payne's gray

payne's grey

peasant's revolt

penn'orth

people's liberation army

people's mujahidin of iran

people's party

people's republican army

people's republic of bangladesh

people's republic of china

pere david's deer

peter o'toole

peter seamus o'toole

peter's gland

peter's pence

peyer's patch

pharaoh's ant

pharaoh's chicken

pheasant's-eye

philibert de l'orme

philosopher's stone

philosophers' stone

philosopher's wool

philosophers' wool

photographer's model

pick's disease

pierre charles l'enfant

pig's ears

pigs' feet

pigs' knuckles

pike's peak

pilgrim's journey

pilgrim's progress

pitcher's mound

pj's

planck's constant

planck's law

planck's radiation law

planter's punch

plasterer's float

plato's academy

ploughman's lunch