To ruminate, to deliberate over something. For more than four centuries, to chew on something has meant to think it over. Likening human chewing to that of cows and other ruminants, which bring up food in a cud that is chewed and swallowed again, goes back even further. John Wycliffe’s translation of the Book of Hosea (1382) reads, “Thei chewiden cud upon shete, and wyne, and departiden fro me” (7:14); the King James Version (1611) differs (“They assemble themselves for corn and wine, and they rebel against me”). Nevertheless, half a century before that translation was published, chewing the cud in the sense of deep thinking had made its way into a book of homilies (1547).