The headword (which must be quoted from somewhere) is the aorist participle, masculine nominative plural, of the verb e)nali/skomai, with passive meaning. Same glossing in other lexica; and cf. also Hesychius epsilon2635, glossing the masculine accusative singular e)nalo/nta as sullhfqe/nta, krathqe/nta.
The gloss is the aorist active participle of verb e)mpi/ptw, literally 'I fall in/into'. This verb is often used by orators in the sense of being thrown into prison: see e.g. Dinarchus 2.9, Demosthenes 25.60 ei)s desmwth/rion. It can also be used absolutely (Lucian, Toxaris 28).