Probably from baqaq; pouring forth; Jabbok, a river east of the Jordan -- Jabbok.
see HEBREW baqaq
H2999. Yabboq
יַבֹּק proper name, of a river (√ probably בקק; so Thes after Simonis, Samaritan Di) (ה)יבק מַעֲבַר Genesis 32:23 (where perhaps connected with אבק = יאבק); יַבּ ׳נַ֫חַל Deuteronomy 2:37, ׳יַבּ הַנַּחַל 3:16; Joshua 12:2, יַבֹּק Numbers 21:24 ("" אַרְנֹּן, compare Deuteronomy 3:16; Joshua 12:2), הַיַּבֹּק Judges 11:13, 22 (in both "" ארנון); it empties into Jordan from East, in latitude of Shiloh; northern border of Amorites, Numbers 21:24 (see Di), Judges 11:22; in its upper course it runs south to north, hence (west) border of Ammon, Deuteronomy 3:16 (compare 2:37), Joshua 12:2; modern Wady Zerqa BdPal.181.