os ‧ ten ‧ ta ‧ tious /ˌɒstənˈteɪʃəs◂, -ten- $ ˌɑː-/ BrE AmE adjective
1 . something that is ostentatious looks very expensive and is designed to make people think that its owner must be very rich:
She carried her car keys on an ostentatious gold key ring.
an ostentatious display of wealth
2 . someone who is ostentatious likes to show everyone how rich they are:
He was vain and ostentatious.
—ostentatiously adverb