IPA: /ˌɒs.tənˈteɪ.ʃən/
KK: /ˌɔːstɛnˈteɪʃən/
A showy display intended to attract attention or admiration, often in a way that seems excessive or pretentious.
The ostentation of the wealthy guests at the party was hard to ignore.
Ostentation → It is formed from "ostentare" (meaning to show or display) and the suffix "-ion" (indicating the action or condition). The word "ostentation" refers to the act of showing off or displaying something ostentatiously.
Think of the act of 'showing' ('ostentare') something to others — that's why ostentation means showing off.