syn– or sym– (prefix) – united; acting or considered together. ORIGIN from Greek sun “with, together.”
The ambiguity of the “with” of syn-/sym- is interesting. In some cases “with” is actively social, for instance in symposium, sympathy and synagogue. It involves people together with other people. Other times a passive, constructive “with” applies. Some examples are synthesis, symmetry and synapse.
My current favorite word, synesis has the most interestingly ambiguous use of syn-. Synesis is the Greek word for understanding. It means essentially with-ness, or togetherness. I like thinking that synesis means simultaneously that 1) the parts are grasped together as a synthesis, 2) in such a way that this togetherness can be shown to others and seen with them.
(I also enjoy thinking about the synoptic (“together-seen”) gospels the same way. On one hand, each gospel tells the whole story as a single summary picture, but on the other hand, the three synoptic gospels viewed together tell a much richer story than any one of them could alone.)