Cf. būṣiš ‘like a būṣu-bird’ (CAD B 348, AHw. 143).
Two alternative etymological approaches to būṣu are at hand. The first possibility is to equate it with
būṣu ‘hyena’, assuming a kind of secondary semantic shift from a mammal to a bird. Within the second approach, būṣu ‘hyena’ and būṣu ‘kind of bird’ are kept apart as two different, homonymous lexemes (CAD B 349 and, tentatively, Landsberger 1934:80). This analysis may be corroborated by Mhr. bč̣aʕyōn, missing from ML, but repeatedly attested in Sima 2009, 89:17–18, 63:21 and elsewhere in Sima’s text collection. Sima translates this word either with the general term “Vögel” or as “Krähen”, while Simeone-Senelle 2011:1079 opts for “Tristram’s grackle”.