The Collaborative International Dictionary of English v.0.48:

Prowl \Prowl\, v. t. [imp. & p. p. Prowled; p. pr. & vb. n.
   Prowling.] [OE. prollen to search about; of uncertain
   origin, perh. for proglen, a dim. of prog to beg, or proke to
   poke. Cf. Proke.]
   1. To rove over, through, or about in a stealthy manner;
      esp., to search in, as for prey or booty.
      [1913 Webster]

            He prowls each place, still in new colors decked. --
                                                  Sir P. Sidney.
      [1913 Webster]

   2. To collect by plunder; as, to prowl money. [Obs.]
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Prowl \Prowl\, v. i.
   To rove or wander stealthily, esp. for prey, as a wild beast;
   hence, to prey; to plunder.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Prowl \Prowl\, n.
   The act of prowling. [Colloq.] --Smart.
   [1913 Webster]

WordNet (r) 3.0 (2006):

prowl
    n 1: the act of prowling (walking about in a stealthy manner)
    v 1: move about in or as if in a predatory manner; "The
         suspicious stranger prowls the streets of the town"
    2: loiter about, with no apparent aim [syn: prowl, lurch]

Moby Thesaurus II by Grady Ward, 1.0:

92 Moby Thesaurus words for "prowl":
   bat around, bum, clandestine behavior, clandestinity, couch,
   count ties, cover, covertness, crawl, creep, cruise, divagate,
   drift, flit, furtiveness, gad, gad about, gallivant, go about,
   go on tiptoe, go the rounds, grovel, gumshoe, hit the road,
   hit the trail, hobo, hunting, inch, inch along, jaunt, knock about,
   knock around, lay wait, lie in wait, lurk, meander, mooch,
   nightwalk, nomadize, pad, patrol, peregrinate, pererrate, prowling,
   pussyfoot, ramble, range, range over, roam, rove, run about,
   saunter, scavenge, scour, scrabble, scramble, searching, seeking,
   shadow, shiftiness, sidle, skulk, slink, slinkiness, slyness,
   snake, sneak, sneakiness, stalk, stalking, steal, steal along,
   stealth, stealthiness, straggle, stray, stroll, surreptitiousness,
   tippytoe, tiptoe, tracking, traipse, tramp, underground activity,
   underhand dealing, vagabond, vagabondize, walk the tracks, wander,
   wayfare, worm, worm along