From an unused root meaning to depress; a basin (as deepened out) -- bowl, dish.
סֵ֫פֶל noun [masculine] bowl (√ unknown; perhaps foreign word; Assyrian saplu, bowl, basin (DIHWB 508 SchrCOT 2 Kings 9:2) [occurs as object of tribute or plunder]; Late Hebrew = Biblical Hebrew; סִיפְלָא ᵑ7 bowl, basin, Christian-Palestinian Aramaic (wash-)basin SchwIdioticon 64; Arabic bowl, jar FlLevy NHWB iii,320; Kl. Schr.ii. 556 f. is perhaps loan-word Frä67f.); — absolute הַסּ ׳מְלֹא Judges 6:38; for drinking, construct אַדִּירִים סֵפֶל 5:25 a bowl of (fit for) nobles, huge bowl (GFM).