kus'-tum (usage): In the Old Testament, except, Ge 31:35 where the Revised Version (British and American) renders, better, "manner" (derekh, "way"), the words translated "custom" are choq, chuqqah, "statute," and mishpaT, "judgment." Such passages as Jg 11:39; Jer 32:11, and especially Ezr 3:4 (the King James Version "custom," the Revised Version (British and American) "ordinance"), illustrate the difficulty of deciding upon the proper translation, in cases where "custom" might become "statute," "usage" establish itself as "law." In Le 18:30; Jer 10:3 the reference is to heathen religious practices.
⇒See the definition of custom in the KJV Dictionary
In the New Testament Lu 1:9; 2:42; Ac 6:14; 15:1 (the King James Version "manner"); Ac 16:21; 21:21; 26:3; 28:17 (ethos), and Lu 2:27 from the same Greek root, refer likewise to definitely established religious practices; in every case except Ac 16:21, those of the Jewish law. The Revised Version (British and American) makes the translation of ethos uniform, reading "custom" in Lu 22:39 (the King James Version "wont") and in Joh 19:40; Ac 25:16; Heb 10:25 (the King James Version "manner"). Greek eiothos, from the same root, is rendered "custom" in Lu 4:16 by English Versions of the Bible, and by the Revised Version (British and American) also in Ac 17:2, its only other occurrence in the New Testament. In Joh 18:39; 1Co 11:16 "custom" is the translation of Greek sunetheia, in the sense of "usage" rather than of "law."
F. K. Farr