Meaning

originBorrowed from French haha. The French term attested 1686 in toponyms in New France (present-day Quebec); compare modern Saint-Louis-du-Ha! Ha!. Usual etymology is that an expression of surprise – “ha ha” or “ah! ah!” is exclaimed on encountering such a boundary. In France this is traditionally attributed to the reaction of Louis, Grand Dauphin to encountering such a feature in the gardens of the…

Etymology from Wiktionary, CC BY-SA 3.0