amplify (v.) Look up amplify at Dictionary.com
early 15c., "to enlarge, expand, increase," from Old French amplifier (15c.), from Latin amplificare "to enlarge," from amplus "large" (see ample) + stem of facere "to make, do" (see factitious). Meaning "augment in volume or amount" is from 1570s. Restriction of use to sound seems to have emerged from c. 1915 in reference to radio technology.