1) a group of military operations with a shared purpose, usually in one area (campaign)
2) an edge, point of contact, shared between two things; an apparatus used to join two different computer parts (interface)
the total value of everything except one variable
cooperative
a group (of people, nations etc) as a whole
composite
willing to cooperate
joint, unified
of, belonging to, a corporation
allied
in, showing, complete agreement
in agreement; uncontested
