adapted or appropriate to the purpose or circumstances; fit; suitable

the proper time to plant strawberries.

conforming to established standards of behavior or manners; correct or decorous

a very proper young man.

fitting; right

It was only proper to bring a gift.

strictly belonging or applicable

the proper place for a stove.

belonging or pertaining exclusively or distinctly to a person, thing, or group.

strict; accurate.

in the strict sense of the word (usually used postpositively)

Shellfish do not belong to the fishes proper. Is the school within Boston proper or in the suburbs?

Grammar .

(of a name, noun, or adjective) designating a particular person or thing and written in English with an initial capital letter, as Joan, Chicago, Monday, American.

having the force or function of a proper name

a proper adjective.

normal or regular.

belonging to oneself or itself; own.

Chiefly British Informal . complete or thorough

a proper thrashing.

Ecclesiastical . used only on a particular day or festival

the proper introit.

Heraldry . (of a device) depicted in its natural colors

an oak tree proper.

Informal .

excellent; capital; fine.

good-looking or handsome.

Mathematics . (of a subset of a set) not equal to the whole set.

Archaic . of good character; respectable.

Informal . thoroughly; completely.

Ecclesiastical . a special office or special parts of an office appointed for a particular day or time.

adjective

improper , unacceptable , unsuitable , crass , crude , misbehaving , objectionable , incorrect , substandard , unconventional , general , inappropriate

adjective

able , applicable , appropriate , apt , au fait , becoming , befitting , capable , competent , convenient , decent , desired , felicitous , fit , fitting , good , happy , just , legitimate , meet , qualified , right , suited , true , useful , by the book , by the numbers * , comely , comme il faut , conforming , correct , decorous , demure , de rigueur * , genteel , in line , kosher * , moral , nice , polite , precise , priggish , prim , prissy , prudish , punctilious , puritanical , refined , respectable , seemly , solid , square * , stone , straight * , strait-laced * , stuffy * , absolute , accepted , accurate , arrant , complete , consummate , customary , established , exact , formal , free of error , on target , on the button , on the nose * , on the right track , orthodox , out-and-out * , unmistaken , usual , utter , characteristic , distinctive , idiosyncratic , own , particular , peculiar , private , respective , special , specific , tailor-made , expedient , suitable , deserved , due , merited , rightful , de rigueur , principled , righteous , right-minded , virtuous , bluenosed , old-maidish , strait-laced , stuffy , victorian , acceptable , advisable , allowable , appertinent , apposite , canonical , chaste , condign , conformable , consistent , conventional , ethical , fine , honest , kosher , ladylike , lawful , licit , opportune , sedate , seeming , strict