The headword noun ko/llh (nominative case) is an Ionicism for the normal ko/lla. It occurs in Galen, In Hippocratis librum de fracturis commentarii Vol 18b p. 398 Kühn.
The adjective used to gloss it here itself glossed in the following sentence. The Suda's accusative kollh/enta occurs in Homer, Iliad 15.389 (cf. e.g. Hesychius kappa3336), so there may be corruption and/or over-abbreviation here.
The gloss kolliw=n appears to be the present active participle of an otherwise unattested variant, kollia/w, of the verb kolla/w.