Type of boundary to a garden, pleasure-ground, or park, designed not to interrupt the view and to be invisible until closely approached.
"The gardener planted a dense row of hedges as a haha to hide the wall from passersby while still defining the edge of the park."
In plain English: Haha is an informal way of writing laughter, usually showing that something was very funny.
"His constant laugh is not funny, but his endless haha at bad jokes is becoming annoying."
Usage: Avoid using this term in modern conversation as it is an archaic word for a hidden garden wall; today people use "hedge" or "fence." It does not refer to laughter despite its spelling resembling the onomatopoeia.
An onomatopoeic representation of laughter.
"Haha! She burst out laughing when she saw the cat wearing a tiny hat."
From Middle English haha, ha ha, from Old English ha ha (interjection), ultimately onomatopoeic. Compare Old Frisian haha (interjection), Middle Low German hahā, hahahā (interjection), Middle High German hahā, haha (interjection), all expressions of joy or of laughter.