syllabic (adj.)

late 14c., from Anglo-French sillable, alteration of Old French silabe "syllable" (12c., Modern French syllabe), from Latin syllaba, from Greek syllabē "that which is held together; a syllable, several sounds or letters taken together," i.e. "a taking together" of letters; from syllambanein "take or put together, collect, gather," from assimilated form of syn- "together" (see syn-) + stem of lambanein "to take" (see lemma). The unetymological -le apparently is by analogy with participle and principle.

"consisting of many (usually meaning more than three) syllables," 1741 (polysyllabical is from 1650s), with -ic + Medieval Latin polysyllabus, from Greek polysyllabos; see poly- "much, many" + syllabic. Perhaps modeled on French polysyllabique (1540s).