1. (especially of aircraft wings) angled rearward from the point of attachment
   "aircraft with sweptback wings" 
2. Used of hair
   - backswept

See also: backward, swept

• unknown
• unknown quantity
• unknown region
• Unknown Soldier
• unlabeled
• unlabelled
• unlace
• unlaced
• unlade
• unladen
• unladylike
• unlamented
• unlash
• unlatch
• unlatched
• unlaureled
• unlaurelled
• unlawful
• unlawful carnal knowledge
• unlawfully
• unlawfulness
• unlax
• unlay
• unleaded
• unleaded gasoline