Musical term: with passion.
Also the nickname of the Beethoven Piano Sonata in F minor, opus 57. This piece was dedicated to Graf Franz von Brunsvik (whose daughters were pupils of Beethoven's) and composed in 1804-1805.
By the summer of 1802, Ludwig van Beethoven was depressed almost to the point of suicide because of his advancing deafness. In this mood Beethoven wrote the Heiligenstadt Testament,a searing piece that seems to have freed his spirit enough to allow him to continue producing music.
From that point until the composition of the "Appassionata", Beethoven produced some of his most pivotal works, music that seems to be the foreword to his "second" main period of creativity: the "Kreutzer" Sonata, the earliest work on the opera Fidelio, the "Waldstein" Sonata, and the Third Symphony.
Beethoven had apparently turned inward and begun to produce music only he could fully understand. He had come to the conclusion that his anger at his fate was pointless, and to have decided to carry on making music and using his genius. In this frame of mind he wrote the Appassionata.
More information on this sonata at http://www.allclassical.com/cg/acg.dll?p=acg&sql=2:67107