pianississimoEtymologyPseudo-Italianism, derived from pianissimo with an additional -iss-, instead of the expected Italian pianissimissimo.pianississimo means indicating that the piece is to be played more softly than pianissimo. Lexicurio rates it Sui generis — a strength score of 87 out of 100.advIndicating that the piece is to be played more softly than pianissimo.nounThe dynamic sign indicating that the piece should be played more softly than pianissimo.