Definitions:

1. a word used for misbehaving children noun
   • don't be a silly
2. dazed from or as if from repeated blows adjective
   • knocked silly by the impact
3. inspiring scornful pity adjective
   • The wooer seemed especially silly since they were getting on in years.

Synonyms:

• airheaded
• cockamamie
• cockamamy
• dizzy
• empty-headed
• featherbrained
• giddy
• goofy
• light-headed
• lightheaded
• pathetic
• punch-drunk
• ridiculous
• sappy
• wacky
• whacky