infusion (n.) Look up infusion at Dictionary.com
c. 1400, "a liquid extract (obtained by soaking in water);" early 15c., "a pouring in; that which is poured in," from Old French infusion "injection" (13c.) or directly from Latin infusionem (nominative infusio) "a pouring in, a watering," noun of action from past participle stem of infundere "to pour into" (see infuse).