synergy (n.) Look up synergy at Dictionary.com
1650s, "cooperation," from Modern Latin synergia, from Greek synergia "joint work, assistance, help," from synergos "working together," related to synergein "work together, help another in work," from syn- "together" (see syn-) + ergon "work" (see urge (v.)). Meaning "combined activities of a group" is from 1847.