de·cre·scen·do 
(dā′krə-shĕndō, dē′-) Music
(dā′krə-shĕndō, dē′-) Music adv. & adj. Abbr. dec.
With gradually diminishing force or loudness. Used chiefly as a direction.
n. pl. de·cre·scen·dos
1. A gradual decrease in force or loudness.
2. A decrescendo passage.
[Italian, gerund of decrescere, to decrease, from Latin dēcrēscere; see DECREASE.]