Balloon , absurd, footling, dazed, airhead, and alec are synonyms for silly; sensible and rational are antonyms of silly. On this page, you will find 192 another word for silly.
1. foolish
2. trivial
3. senseless
4. nincompoop
That was a really silly mistake.
She wore a silly hat today.
Stop being silly and focus now.
He told a very silly joke.