From an unused root meaning to deepen; properly, a pail; but generally of earthenware; a jar for domestic purposes -- barrel, pitcher.
H3537. kad
כַּד noun feminine jar (Late Hebrew id.; Aramaic כַּדָּא) — כַּד absolute 1 Kings 17:12; Ecclesiastes 12:6; construct 1 Kings 17:14, 16; כַּדֵּךְ Genesis 24:14, 17, 43 etc.; plural כַּדִּים Judges 7:16 (twice in verse) + 3t.; — water-jar, carried on woman's shoulder Genesis 24:14-15, 16, 17, 18, 20, 43, 45, 46 (all J), 1 Kings 18:34; Ecclesiastes 12:6; empty (of water), containing lamps Judges 7:16, 19, 20; containing meal 1 Kings 17:12, 14, 16. (On extra-Palestinian history of this word compare LagBN 104.)