( n. )
An active power or cause; that which has the power to produce an effect; as, a physical, chemical, or medicinal agent; as, heat is a powerful agent.
( n. )
An active power or cause; that which has the power to produce an effect; as, a physical, chemical, or medicinal agent; as, heat is a powerful agent.
Webster's Revised Unabridged English Dictionary. Пересмотренный полный словарь английского языка Webster. 2012