The headword is the superlative, neuter nominative/accusative plural, of the adjective ἡδύς “pleasant” (see eta 91 and eta 92), glossed here in its adverbial sense.
Although literally taken from the Synagogè (Lexica segueriana eta249, Bachmann), this is an entry which is similarly glossed in several different lexicographic sources: Photius, Lexicon Ambrosianum, Glossarium Cyrilli and Hesychius (probably interpolated by Cyril).