sunk fence vs haw-haw

sunk fence and haw-haw both are nouns.

Word	Noun	Adjective	Verb	Adverb
sunk fence	Yes	No	No	No
haw-haw	Yes	No	No	No

As nouns, sunk fence and haw-haw are synonyms defined as:

sunk fence and haw-haw: a ditch with one side being a retaining wall; used to divide lands without defacing the landscape

Other synonyms of sunk fence include ha-ha.

sunk fence (noun)	haw-haw (noun)
a ditch with one side being a retaining wall; used to divide lands without defacing the landscape	a ditch with one side being a retaining wall; used to divide lands without defacing the landscape
	a loud laugh that sounds like a horse neighing