Similarly already in Hesychius epsilon3310: headword there spelled e)nstrobili/sas and gloss not but suntri/yas but sustre/yas -- the latter also in Photius, Lexicon epsilon1022. The headword (however spelled) is the aorist active participle, masculine nominative singular, of a verb e)nstrobile/w. It is otherwise unattested, but cf. generally stro/bilos round ball, cyclone, whirling dance, pinecone (sigma 1207).