haw-haw

n. [ Duplication of haw a hedge. ] 1. See Ha-ha. [ 1913 Webster ]

2. a loud laugh that sounds like a horse neighing. [ wns=1 ]
Syn. -- hee-haw, horselaugh, ha-ha. [ WordNet 1.5 ]

3. a sunken fence (so as not to interfere with the view). [ wns=3 ]
Syn. -- haha. [ WordNet 1.5 ]