From the same as becer -- sour grape.
see HEBREW becer
H1155. boser
בֹּ֫סֶר noun masculineIsaiah 18:5 unripe or sour grapes collective (Late Hebrew id., Aramaic בּוּסְרָא, (PS; syllable uncertain [Nes, privately]; Polyglotts and Castell have ); Arabic unripe dates) — בֹּסֶר 18:5 3t. בִּסְרוֺ Job 15:33; — unripe grapes Isaiah 18:5; Job 15:33; sour g. Jeremiah 31:29-30, Ezekiel 18:2.
בעד (Arabic , be remote, distant, Qor 9:42, distant; Ethiopic to change, Psalm 33 title, different, distinct, another).