1. Someone being or trying to be irritatingly clever; a smart alec
   - bright spark, smart-ass [N. Amer], smartypants, smarty, smartie

Derived forms: smart-arses

• understandably
• understanding
• understandingly
• understate
• understated
• understatement
• understock
• understood
• understrength
• understructure
• understudy
• undersurface
• undertake
• undertaker
• undertaking
• underthings
• undertide
• undertone
• undertow
• undervaluation
• undervalue
• undervest
• underwater
• underwater archaeology
• underwater archeology