The Collaborative International Dictionary of English v.0.48:

Mew \Mew\, v. i. [Of imitative origin; cf. G. miauen.]
   To cry as a cat. [Written also meaw, meow.] --Shak.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Meow \Me*ow"\, v. i. & n.
   See 6th and 7th Mew.
   [1913 Webster]

WordNet (r) 3.0 (2006):

meow
    n 1: the sound made by a cat (or any sound resembling this)
         [syn: meow, mew, miaou, miaow, miaul]
    v 1: cry like a cat; "the cat meowed" [syn: meow, mew]