From kabar; vast, whether in extent (figuratively, of power, mighty; of time, aged), or in number, many -- + feeble, mighty, most, much, strong, valiant.
see HEBREW kabar
H3524. kabbir
כַּבִּיר adjective great, mighty, much only in poetry, and only Job, Isa1: — Isaiah 10:13 Qr (but read as Kt כְּאַבִּיר), 17:12; and 28:2 כבירים מים (usually רַבִּים מַיִם), Job 8:2 פיך אמרי כביר ורוח a mighty wind, 15:10 ימים מאביך כביר (Ges§ 131, R 5a) = aged: of God, 34:17 צַדִּיק כַּבִּיר the just mighty one, 36:5 a, vb ׳כ לֵב כֹּחַ mighty in strength of understanding; 34:24 כבירים mighty men; of quantity = much, Isaiah 16:14 כַבִּיר לוֺא מִזְעָר מְעַט שְׁאָר, Job 31:25 ידי מצאה כביר וכי had gotten much.