5
idle
5
ill-advised(adjective, weak, simple, careless, foolish)
5
ill-considered(adjective, weak, simple, foolish, stupid)
5
lunatic(adjective, weak, simple, knowledge, ability)
5
maudlin(soft, sweet, foolish, emotional, wet)
5
sheepheaded(adjective, characteristic, foolish, absurd, stupidity)
5
weak-minded(adjective, ability, planned)
5
whacky
4
birdbrained(adjective, slang, ability, foolish, stupid)
4
blockhead(noun, simple, fool, innocent, jerk)
4
numskull(noun, simple, fool, innocent, jerk)
4
rattle-brained
4
simple-minded(adjective, foolish, stupid, green, fat)
4
slight(adjective, detail, small, trivial, worthless)
4
barmy(adjective, foolish, crazy, mad, trivial)
4
bird-brained(adjective, giddy)
4
bonehead(noun, simple, fool, innocent, jerk)
4
clod(noun, simple, fool, innocent, jerk)
4
confused(careless, stupid, unthinking, obtuse, unperceptive)
4
cracked(adjective, wild, foolish, stupid, crazy)
10 years ago|39k views|share |citing 
APASmart Define. (2016). silly thesaurus. Retrieved September 21, 2026, from https://smartdefine.org/silly/thesaurus/synonyms
ChicagoSmart Define. 2016. "silly thesaurus" https://smartdefine.org/silly/thesaurus/synonyms (accessed September 21, 2026).
HarvardSmart Define 2016, silly thesaurus, Smart Define, viewed 21 September, 2026, <https://smartdefine.org/silly/thesaurus/synonyms>.
MLASmart Define. "silly thesaurus" 20 January 2016. Web. 21 September 2026. <https://smartdefine.org/silly/thesaurus/synonyms>