From an unused root meaning to define; a seah, or certain measure (as determinative) for grain -- measure.
H5429. seah
סְאָה noun feminine (see below) se'ah, a measure of flour, grain, etc. (√ unknown; perhaps foreign word; Late Hebrew id.; Aramaic סָאתָא סְאָה,, , , (Greek σάτον, LewyFremdwörter 116 f)); — absolute סְאָהֿ 2 Kings 7:1, 16, וּסֳאָהֿ 7:18 (Baer Ginsb compare Ges§ 10h); dual סָאתַיִם 1 Kings 18:32 3t.; plural סְאִים Genesis 18:6; 1 Samuel 25:18; — always with appositive of thing measured, Genesis 18:6 (J), 1 Samuel 25:18; 1 Kings 18:32; 2 Kings 7:1 (twice in verse); 7:16 (twice in verse); 7:18 (twice in verse) (where apparently masculine, perhaps after analogy of other measures of capacity, כֹּר תֹמֶר, הִין,, etc., AlbrZAW xvi (1896), 95); — סַאסְּאָה Isaiah 27:8 see סאסא. — On size of se'ah = 1/3 ephah, = 12.148 litres (= 10.696 qts.), see NowArchaeology i. 203 BenzArchaeology 183.