ac·cel·er·an·do 
(ä-chĕl′ə-rändō) Music
(ä-chĕl′ə-rändō) Music adv. & adj.
Gradually accelerating or quickening in time. Used chiefly as a direction.
n. pl. ac·cel·er·an·dos
An accelerando passage or movement.
[Italian, present participle of accelerare, to hasten, from Latin accelerāre; see ACCELERATE.]