What word does your mother always say?
c.1200, "habitual practice," from Old French costume "custom, habit, practice; clothes, dress" (12c., Modern French coutume), from Vulgar Latin *consuetumen, from Latin consuetudinem (nominative consuetudo) "habit, usage, way, practice, tradition, familiarity," from consuetus, past participle of consuescere "accustom," from com-, intensive prefix (see com-), + suescere "become used to, accustom oneself," related to sui, genitive of suus "oneself," from PIE *swe- "oneself" (see idiom). Replaced Old English þeaw. Sense of a "regular" toll or tax on goods is early 14c. The native word here is toll.
"made to measure or order," c.1830, from custom (n.).
a tax imposed by the Romans. The tax-gatherers were termed publicans (q.v.), who had their stations at the gates of cities, and in the public highways, and at the place set apart for that purpose, called the "receipt of custom" (Matt.9: 9; Mark 2:14), where they collected the money that was to be paid on certain goods (Matt.17:25). These publicans were tempted to exact more from the people than was lawful, and were, in consequence of their extortions, objects of great hatred. The Pharisees would have no intercourse with them (Matt.5:46, 47; 9:10, 11). A tax or tribute (q.v.) of half a shekel was annually paid by every adult Jew for the temple. It had to be paid in Jewish coin (Matt. 22:17-19; Mark 12:14, 15). Money-changers (q.v.) were necessary, to enable the Jews who came up to Jerusalem at the feasts to exchange their foreign coin for Jewish money; but as it was forbidden by the law to carry on such a traffic for emolument (Deut. 23:19, 20), our Lord drove them from the temple (Matt. 21:12: Mark 11:15).