As the relation of contractor and contractee is voluntary, the consequences attaching to the relation must be voluntary.
early 14c., from Old French contract (Modern French contrat), from Latin contractus "a contract, agreement," from past participle of contrahere "to draw together," metaphorically, "to make a bargain," from com- "together" (see com-) + trahere "to draw" (see tract (n.1)). U.S. underworld sense of "arrangement to kill someone" first recorded 1940.
contract con·tract (kən-trākt', kŏn'trākt')
v. con·tract·ed, con·tract·ing, con·tracts
To reduce in size by drawing together.
To become reduced in size by or as if by being drawn together, as the pupil of the eye.
To acquire or incur by contagion or infection.
A legally binding agreement between two or more parties.