Meaning

noun accepted or habitual practice

noun a specific practice of long standing

noun money collected under a tariff

originPIE word *ḱóm PIE word *swé From Middle English custume, borrowed from Anglo-Norman custume, inherited from Latin consuētūdinem, a noun derived from cōnsuēscō, from con- (“with”) + suēscō (“become used or accustomed to”). Displaced native Old English ġewuna. Doublet of costume, consuetude, and kastom. The adjectival form first appears c. 1830.

Etymology from Wiktionary, CC BY-SA 3.0