Definitions for "Anacrusis"
A prefix of one or two unaccented syllables to a verse properly beginning with an accented syllable.
an incomplete bar (it contains fewer beats than are required by the time signature)
a group of notes at the start of a phrase of music that fall before the main beat or pulse of the actual piece
Anacrusis was a progressive/melodic thrash metal band from St. Louis, MO. Anacrusis was one of the first bands that attempted to blend thrash and progressive metal.