The headword, evidently extracted from somewhere, is the aorist indicative active, third person singular, of the rare verb suneisfre/w, I let in together; see generally LSJ s.v.
[1] The gloss is the aorist indicative active [imperfect in ms G, Adler reports], third person singular, of the verb suneisfe/rw, I join in carrying in, contributing, especially as applied to paying extraordinary taxes and levies; see generally LSJ s.v. The headword is identically glossed by Hesychius (sigma2493), the Synagoge (sigma337), Photius (Lexicon sigma761 Theodoridis), and ps.-Zonaras 1693.4.