PIANISSIMO Meaning of PIANISSIMO in English adj., adv., & n. Mus. adj. performed very softly. adv. very softly. n. (pl. -os or pianissimi) a passage to be performed very softly. [ It., superl. of PIANO(2) ] Concise Oxford English dictionary. Краткий оксфордский словарь английского языка. 2012