(disapproving) showing your wealth or status in a way that is intended to impress people (Oxford)
(of an action) done in a very obvious way so that people will notice it (Oxford)
too obviously showing your money, possessions, or power, in an attempt to make other people notice and admire you (Cambridge)
He gave an ostentatious yawn. (Oxford)
They criticized the ostentatious lifestyle of their leaders. (Cambridge)
an ostentatious yawn.
ostentatious lifestyle
Extravagant
Boastful
Modest
Moderate
Ostentatiously