1. An active force or substance capable of producing an effect. For agents not listed here, see the specific name.

2. Referring to disease, a factor such as a microorganism, chemical substance, or form of radiation whose presence, excessive presence, or relative absence (as in deficiency diseases) is essential for the occurrence of a disease.


[L. ago, pres. p. agens (agent-), to perform]

adrenergic blocking agent

adrenergic neuronal blocking agent

alkylating agent

antianxiety agent

antifoaming agents

antipsychotic agent

bacteriostatic agent

Bittner agent

blister agent

blocking agent

calcium channel-blocking agent

chimpanzee coryza agent

cholinergic agent

contrast agent

delta agent

Eaton agent

embedding agents

enterokinetic agent

F agent

fertility agent

foamy agents

ganglionic blocking agent

high osmolar contrast agent

initiating agent

inotropic agents

LDH agent

luting agent

MS-1 agent

MS-2 agent

neuroleptic agent

neuromuscular blocking agents

nondepolarizing neuromuscular blocking agent

Norwalk agent

Pittsburgh pneumonia agent

promoting agent

psychotropic agent

reovirus-like agent

sclerosing agent

slow channel-blocking agent

sympathetic agent

transforming agent

TRIC agents