The Kabeiroi or Cabiri were divinities at certain Greek mystery sanctuaries, esp. Thebes (Boiotia), Lemnos and Samothrace; the name is of Semitic origin (from kabir, "lord"). See generally OCD(4) s.v. Cabiri.
Though hard to disentangle, the present entry appears to recognize the use of the term Kabeiroi/Cabiri -- over and above its existence in the sense already mentioned -- in a more purely geographical sense. Besides (e.g.) the "Kabeireion" in Boiotia and on Lemnos, there was a Kabeira in Pontos (Barrington Atlas map 87 grid B4). That name is neuter plural, and the otherwise unattested *Kabeirw=n of the present entry might be its genitive plural. (NB: Adler's punctuation indicates that she understood the first two words of this entry not as headword plus gloss, as e.g. kappa 7, but a two-word phrase.)
[1] On this last point cf. Photius, Lexicon kappa3 and elsewhere.