v1.0
Published 01/10/24
colbh m. [kʰɔɫ̪͡ɔv], gen. cuilbh [kʰu̟l͡u̟v], [kʰul͡uv], and Ir. colbh[a] in the sense ‘stick’ are derived by Craigie (1894, 157: ‘Stok’) from ON kólfr m., leg. kolfr 
But Ice. kólfr (Cleasby 1874).
‘a stake, straight rod; bell’s tongue; bolt; arrow bolt’ (NO), so also de Vries (1962), 
In quoting Craigie, de Vries erroneously labels modern Ir. colbh ‘altirisch’ [Old Gaelic].
while McDonald (2009, 375) considers the loan unlikely on semantic grounds.
Craigie also cites righ-colbh ‘sceptre’, but this should read SG rìgh-cholbh (Dwelly 1911), Ir. ríogh-cholbh (Dinneen 1947).
While ON kolf acc. might formally yield SG colbh, cf. SG Calbha NC167367 < ON *Kalf-ø̨y ‘(the) calf-island’, SG colbh ‘sceptre; post, pillar; plant, stalk; the front of a bed; reed’ (Dwelly 1911 
Dwelly also gives the sense ‘wile’, after Alexander Carmichael in CG I, 22: bho chuilbh an fhir-cheilg ‘from the wiles of the deceiver’, although colbh (pl. cuilbh) here is conceivably a back-formation from SG cuilbheart ‘wile, trick, deceit, cunning, craft’ (Dwelly 1911).
) and Ir. colbha ‘(outer) edge, side; ledge; column; support’ (Ó Dónaill 1977, s.v. 1, 2colbha) go back to EG colḃa ‘platform; seat; outer edge of a bed; support’ (eDIL˄), which has been seen as a possible loan-word from, but more recently (along with W celfi ‘column, pillar, post’) as cognate with, Lat. cŏlumna ‘column etc.’ (e.g. MacBain 1911; 
MacBain sees SG colbh in the senses ‘plant, stalk’ as allied to Lat. culmus ‘stalk, stem’ rather than cŏlumna; while this is possible, they might easily be extended senses of ‘post, pillar’ etc.
Marstrander 1915a, 122; Pokorny 1959 II, 544; Vendryes 1996; GPC˄).
Derivatives: in addition to SG calbh m., via o ~ a alternation, which has the senses ‘shoot’ and ‘rib of an osier basket’ (e.g. Dwelly 1911) and, by extension, ‘partition’ (Watson 2022, 135), there is the feminine derivative cailbhe ‘partition’ (e.g. Dwelly).