a ditch, one side of which is made into a retaining wall so as to enclose an area of land while remaining hidden in the total landscape
Also called: ha-ha
sunk fence in American English
noun
a wall or other barrier set in a ditch to divide lands without marring the landscape
Word origin
[1755–65]This word is first recorded in the period 1755–65. Other words that entered Englishat around the same time include: buckeye, caucus, insurgent, outfit, stalemate