Old Irish lobur‘weak, sick; leprous’ is cognate with Welshl lwfr‘cowardly,timid, faint-hearted; mean; idle’, Cornish lover, Middle Breton loffr, Modern Breton lovr‘weak, miserly, leprous’. The common notion linking these words semantically is ‘weak’. Because of the voca lism of the Welsh word, the Proto-Celtic reconstruction *lobro-, proposed in earlier scholarship (VGKSi 116‒17,Deshayes 2003: 477), is excluded: Proto-Celtic (PC) *oappears asoin all British-Celtic languages (SchRijveR 1995: 26), except for certain nasal contexts and before *RC‒ neither of which is applicable here ‒, where it is raised tou<w>in Welsh (SchRijveR 1995: 27‒44, 52–68); PC *u, on the other hand, is retain edasu<w> in Welsh, but yields oin Cornish and Breton (SchRijveR 1995: 26‒7),precisely the distribution found in this etymon. Theoof OIr.loburis due to the regular lowering of PC *u>o before a non-high back vowel (McCone 1996: 110). The voiced labial fricative evidenced in the individual languages can continue Proto-Celtic *bor *φ. The former is the reflex of Indo-European *bh, *gu̯and the marginal sound *b(McCone 1996: 42‒3; Stifter 2017: 1189‒90), whereas the latter continues word-internal Indo-Euro pean *p before a liquid (McCone1996: 44; Stifter 2017: 1190)