arch in WordNet English dictionary

1. form an arch or curve
   "her back arches"; "her hips curve nicely"
   arch  curve  arc 
   

1. (architecture) a masonry construction (usually curved) for spanning an opening and supporting the weight above it
   arch 
   
2. a passageway under a curved masonry construction
   "they built a triumphal arch to memorialize their victory"
   arch  archway 
   
3. a curved bony structure supporting or enclosing organs (especially the inner sides of the feet)
   arch 
   
4. a curved shape in the vertical plane that spans an opening
   arch 
   

1. naughtily or annoyingly playful
   "teasing and worrying with impish laughter"; "a wicked prank"
   arch  impish  implike  mischievous  pixilated  prankish  puckish  wicked 
   
2. expert in skulduggery
   "an arch criminal"
   arch 
   
3. (used of behavior or attitude) characteristic of those who treat others with condescension
   arch  condescending  patronizing  patronising