The headword as transmitted appears to be the perfect active participle, masculine/neuter genitive plural, of a compound verb e)nqa/llw, attested only in lexicography. (It is glossed with the equivalent form of the present participle of simple qa/llw.) But Bachmann's Lexicon (in the Lexica Segueriana) proffers the more regular form e)nteqhlo/twn. If that is authentic, it might be quoted from its only other extant occurrence, in Cyril of Alexandria, Commentary on Isaiah PG 70.25.50.
cf. Hesychius epsilon3327, with corresponding adverbial forms: e)nteqhlo/tws glossed with, apparently, qallo/ntws.