ˌshow pony BrE AmE noun ( plural show ponies ) [countable]
1 . a ↑ pony (=small horse) that takes part in a competition which involves jumping fences or being judged on appearance
2 . informal someone who is confident and enjoys being with other people, but who often tries to show how clever or skilled they are so that other people will admire them – used humorously SYN show-off