Arabic

bulˁum- - gullet, œsophagus (BK 1 161, Lane 249)

Note also balˁat­- ‘trou dans la meule’ [ibid. 161] and bulaˁ- ‘trou de la poulie’ [ibid.] (both lit. ‘gorge’?).

PWS
*balVˁ/γ-, *balˁVm- - uvula; gullet, gorge (SED I No. 36)
Usually regarded as related to, or derived from, Sem. *blˁ ‘to swallow’ (cf. [DRS 68], [LGz. 925]); this verb, however, denitely points to ˁ (so in Arb. and MSA), while the noun under consideration shows oscillation ˁ/γ in MSA and, likely, Arb. Note variant stems with *-m in Arb. (cf. also blˁm ‘avaler’ [BK 1 161]), Mnd. (unless an Arabism) and Soq., which may be regarded as common Sem., and *ta-­ in MSA.