This Slavic base type can be found in the written sources of Old Church Slavonic. Some of today's standard Slavic languages adopted this type:
hbs. žlijȇb, dial.
rus. žólob,
slk. žl'ab,
pol. żłób, all meaning 'feeding trough'. In Proto-Slavic,
*žȇlbъ was probably a term for SOMETHING HOLLOWED. Therefore, the functional extension of the meaning to 'feeding trough' is plausible. The base type is related to
grc. gláphō (γλάφω) 'to hollow out',
grc. gláphy (γλάφῠ, n.) 'cave, valley',
sga. gulban 'spike, beak',
cym. gylf 'beak' and the Gallo-Roman
gulbia 'chisel, gouge'. (cf. SNOJ, under
žlẹ̑b).