D defs.my
Entry 1 sense Webster, 1913

Ruga

· Ru·ga · IPA /ˈɹuː.ɡə/
01 n. A wrinkle; a fold; as, the rugae of the stomach.
pl. Rugae ((#))
  1. 1.
    A wrinkle; a fold; as, the rugae of the stomach.(Nat. Hist.)