show-off

show-off
ˈshow-off noun [countable] informal
someone who always tries to show how clever or skilled they are so that other people will admire them – often used to show disapproval:
    She’s a bit of a show-off.

show-offBrE /ˈʃəʊ ɒf/ 🔊NAmE /ˈʃoʊ ɔːf/ 🔊, /ˈʃoʊ ɑːf/ 🔊 noun (informal, disapproving) a person who tries to impress other people by showing how good he or she is at doing sth 爱炫耀的人；喜欢卖弄的人