Variants: libbuḫu, ilibbuḫu, ellambuḫu, ilbuḫu, illabuḫu, ellabuḫu. Von Soden suggests that this is a Sum. loanword (see a detailed discussions in [Lieberman 222]). Part of the forms with prefixed ˀi- (< *ˀa- influenced by -i- of the second syllable implying *ˀa-libbuḫ- ?).
Scarce but reliable attestation: only Akk. and Arb.