System  n. 1 complex whole; set of connected things or parts; organized body of things. 2 a set of organs in the body with a common structure or function. B human or animal body as a whole. 3 method; scheme of action, procedure, or classification. 4 orderliness. 5 (prec. By the) prevailing political or social order, esp. Regarded as oppressive.  get a thing out of one's system colloq. Get rid of a preoccupation or anxiety. [greek sustema -mat-]