control

I. verb (controlled; controlling) Etymology: Middle English countrollen, from Anglo-French contrerouler, from contreroule copy of an account, audit, from Medieval Latin contrarotulus, from Latin contra- + Medieval Latin rotulus roll — more at roll Date: 15th century transitive verb 1. a. archaic to check, test, or verify by evidence or experiments b. to incorporate suitable controls in <

a controlled experiment

> 2. a. to exercise restraining or directing influence over ; regulate b. to have power over ; rule c. to reduce the incidence or severity of especially to innocuous levels <

control an insect population

> <

control a disease

> intransitive verb to incorporate controls in an experiment or study — used with for <

control for socioeconomic differences

> Synonyms: see conduct • controllability noun • controllable adjective • controlment noun II. noun Usage: often attributive Date: 1590 1. a. an act or instance of controlling; also power or authority to guide or manage b. skill in the use of a tool, instrument, technique, or artistic medium c. the regulation of economic activity especially by government directive — usually used in plural <

price controls

> d. the ability of a baseball pitcher to control the location of a pitch within the strike zone 2. restraint, reserve 3. one that controls: as a. (1) an experiment in which the subjects are treated as in a parallel experiment except for omission of the procedure or agent under test and which is used as a standard of comparison in judging experimental effects — called also control experiment (2) one (as an organism, culture, or group) that is part of a control b. a device or mechanism used to regulate or guide the operation of a machine, apparatus, or system c. an organization that directs a spaceflight <

mission control

> d. a personality or spirit believed to actuate the utterances or performances of a spiritualist medium Synonyms: see power