outer; being on the outer side

the exterior surface; exterior decorations.

intended or suitable for outdoor use

exterior paint.

situated or being outside; pertaining to or connected with what is outside

the exterior territories of a country.

the outer surface or part; outside.

outward form or appearance

She has a placid exterior, but inside she is tormented.

Mathematics . the collection of points not contained in the closure of a given set.

adjective

central , interior , middle

noun

center , core , interior , middle

adjective

exoteric , external , extraneous , extraterrestrial , extraterritorial , extrinsic , foreign , marginal , outdoor , outer , outermost , outlying , outmost , outward , over , peripheral , superficial , surface

noun

appearance , aspect , coating , cover , covering , exteriority , external , facade , face , finish , outside , polish , rind , shell , skin , superficies , superstratum , surface , ectal , outer , outermost