1
general::
Display in an ostentatious, conspicuous way; also, seek attention by displaying one's accomplishments, abilities, or possessions. For example, I'm wearing shorts to show off my Florida tan, or Karen loved showing off her new baby to her friends, or There's no need to show off, Fred; we all know you're a good dancer. [Early 1800s]
American Heritage Idioms
2
general::
Phrase(s): show off
to do things in a way that is meant to attract attention. • Please stop showing off! You embarrass me. • John is always showing off to his girlfriend., Phrase(s): show someone or something off
to display someone or something so that the best features are apparent. • Bill drove around all afternoon showing his new car off. • Mrs. Williams was showing off her baby to the neighbors.
McGrawhill's American Idioms And Phrasal Verbs