‘Show off’ is a B2 level phrasal verb with a negative meaning. It means to attract attention to yourself by doing things that other people find annoying. For example if you are good at dancing and keep showing people how good you are just to try and get attention then you are showing off.
She couldn’t really afford the sports car, but bought it anyway because she just wanted to show (3)…… to her friends.
Examiner: “Why do you think it is so important for some people to always have the latest mobile phone”
Candidate: “Well, I’d say most of the time it is simply because they want to show off to their friends…”