WordNet sense 1 (the state that exists when one person or group has power over another):

ascendance, ascendancy, ascendency, dominance, ascendence

WordNet sense 2 (a standard against which other conditions can be compared in a scientific experiment):

control condition

WordNet sense 3 (great skillfulness and knowledge of some subject or activity):

command, Mastery

WordNet sense 4 (discipline in personal and social activities):

restraint

WordNet sense 5 (a mechanism that controls the operation of a machine):

controller

WordNet sense 6 (verify or regulate by conducting a parallel experiment or comparing with another standard, of scientific experiments):

verify

WordNet sense 7 (lessen the intensity of; temper; hold in restraint; hold or keep within limits):

check, contain, curb, hold, moderate, moderate, hold in

WordNet sense 8 (control (others or oneself) or influence skillfully, usually to one's advantage):

manipulate, keep in line

WordNet sense 9 (handle and cause to function):

operate

WordNet sense 10 (be careful or certain to do something; make certain of something):

ascertain, assure, ensure, insure, see, see to it

WordNet sense 11 (have a firm understanding or knowledge of; be on top of):

master