IPA: /ˈʌpˌmænʃɪp/
KK: /ˈʌpˌmænʃɪp/
The practice of trying to show that you are better than someone else, often by boasting or competing in a clever way.
His constant one-upmanship made it hard for others to feel comfortable around him.
Upmanship → The word is formed from 'up' (meaning higher or superior) and 'manship' (from Old English 'man' meaning person and 'ship' meaning condition or quality). The term describes the condition of being superior or better than others, particularly in a competitive context.
Think of someone trying to be 'higher' or 'better' ('up') than others in a competitive situation, which is what 'upmanship' means.