for ‧ tis ‧ si ‧ mo /fɔːˈtɪsəməʊ, fɔːˈtɪsɪməʊ $ fɔːrˈtɪsəmoʊ/ BrE AmE adjective , adverb
[ Date: 1700-1800 ; Language: Italian ; Origin: 'loudest' , from forte ; ⇨ ↑ forte 1 ]
music that is fortissimo is played or sung very loudly OPP pianissimo ⇨ forte