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]

Moby Thesaurus II by Grady Ward, 1.0:

43 Moby Thesaurus words for "meow":
   bark, bawl, bay, bell, bellow, blare, blat, blate, bleat, bray,
   call, caterwaul, cry, give tongue, give voice, howl, low, mew,
   mewl, miaow, moo, neigh, nicker, pule, roar, screak, scream,
   screech, squall, squeak, squeal, troat, ululate, wail, whicker,
   whine, whinny, yap, yawl, yawp, yelp, yip, yowl