The unglossed headword appears in the Ambrosian Lexicon (according to Adler) as well as ps.-Herodian and Hesychius sigma2234, but spelled there with single rho, sukomore/a; the Suda's double rho spelling, here twice, is otherwise unattested.
Adler makes no comment on the note, but TLG searching shows that it is derived from Theodoret, Interpretation of the 12 minor prophets PG 81.1700. Dried fruits of the sycamore-fig (Ficus sycomorus) are found in Egyptian tombs with marks of the gashing which induces ripening: see Wikipedia entry at web address 1. This is the kind of sycamore which Zacchaeus climbed in order to see Jesus (Luke 19.4).
The present-day European and North-American tree known as "sycamore" is not related to this tree, but rather to the plane tree (genus Platanus).