A primitive root; properly, to burst the womb, i.e. (causatively) bear or make early fruit (of woman or tree); also (as denominative from bikkuwr) to give the birthright -- make firstborn, be firstling, bring forth first child (new fruit).
see HEBREW bikkuwr
H1069. bakar
[בָּכַר] verb (Late Hebrew בְּכֵּר, Aramaic בַּכֵּר, ; compare Arabic rise early, do anything early; , virgin, woman having her first child; Ethiopic primogenitus; Assyrian bukru, first-born, Dl§ 65, 5) —
Pi`el Imperfect יְבַכֵּר Ezekiel 47:12; Infinitive לְבַכֵּר Deuteronomy 21:16; —
1 bear early, new fruit Ezekiel 47:12.
2 make or constitute as first-born Deuteronomy 21:16 (denominative of בכיר).
Pu`al Imperfect יְבֻכַּר Leviticus 27:26 born or made a firstling.
Hiph`il Participle f. מַבְכִּירָה Jeremiah 4:31 one bearing her first child.