Where does “coustume” come from?
coustume (Middle French) comes from Old French coustume, from Vulgar Latin consuetumen, from Latin cōnsuētūdō, from Latin cōnsuēscō, from Latin suēscō, from Proto-Indo-European swe-dʰh₁-sk-, from Proto-Indo-European dʰeh₁- — to do, put, place.
coustume (Middle French): custom; tradition
Ancestry of “coustume”, step by step