From Sum. (giš)BA.TUR. A late (possibly, “learned”) borrowing.
Derived words: baṭiltu 'interruption' (CAD B 176, AHw. 116); baṭlu 'ceased' (CAD B 177, AHw. 116); biṭiltu (mng. uncert.) (CAD B 297, AHw. 134).
No etymology can be suggested.
From Sum. BAD 'to open' (PSD B 33), also used as a sign name (Gong 2000, 104f.).
While the WS origin of this lexeme is relatively certain, its further etymological analysis is severely hampered by the orthographic ambiguity of the signs rendering the latter two radicals (Streck 2000, 85f.).
Derived words: baziˀtu 'claim' (CAD B 185).
No definitive etymology can be suggested.
Probably of foreign origin. An Egyptian etymology is surmised by Kogan (apud Arkhipov 2018, 168, fn. 5).
Or basku etc.
Perhaps an onomatopoeic word imitating the characteristic sound produced by ducks.