Same entry already in Hesychius (epsilon3306) and elsewhere. The headword is aorist middle participle, masculine nominative singular, of the verb e)nsterni/zw or e)nsterni/zomai (which derives from ste/rnon (sternum) "breast, chest"; cf. sigma 1053; see also pi 2396, with a related verb similarly glossed). It must be quoted from somewhere; instances outside lexicography are very few but include one in John Chrysostom, Homily on Paul's Letter to the Ephesians (PG 62.168.42).