amplify
Pronunciation: /ˈamplɪfʌɪ/
verb ( amplifies, amplifying, amplified)
- 1increase the volume of (sound), especially using an amplifier: (as adjective amplified) amplified pop music
- increase the amplitude of (an electrical signal or other oscillation): the manufacturers have developed a system of amplifying the radio signal
- make (something) more marked or intense: urban policy initiatives amplified social polarization

Origin:
late Middle English (in the general sense 'increase, augment'): from Old French amplifier, from Latin amplificare, from amplus 'large, abundant'