/ ˌɒstenˈteɪʃəs; NAmE ˌɑːs-/ adjective
1.
( disapproving ) expensive or noticeable in a way that is intended to impress people
SYN showy
2.
( disapproving ) behaving in a way that is meant to impress people by showing how rich, important, etc. you are
3.
( of an action ) done in a very obvious way so that people will notice it :
He gave an ostentatious yawn.
► os·ten·ta·tious·ly adverb :
ostentatiously dressed