Synarthrosis: an articulation without motion.
Syncerebrum: the compound brain of insects.
Synchronous: happening at the same time.
Synciput: that portion of the vertex lying between the eyes.
Syncitium: masses of protoplasm with nuclei, found in ovarian tubes; giving rise to ova, nutritive cells or both.
Syndesis: that method of articulation where two parts are connected by a membrane which permits of considerable motion between them.
Synechtry: the relation borne to ants by insects inhabiting their nests in spite of the efforts of the ants to destroy them: see symphily and metochy.
Synista or Synistata: those Neuropterous insects in which the mouth structures are undeveloped, forming an imperfect tubular structure: see elinguata.
Synoecy: the relation that exists between ants and those guests that are indifferent to and tolerated by them:= metochy, and see symphily and synecthry.
Synonym: a name applied to a species or genus that has been previously named and described.