Fortissimo

In dynamics music notation, fortissimo is abbreviated 'ff' and indicates that the music from that point on should be very loud. The word means "very loudly" in Italian.

When added to the staff, it looks something like this (complete with eighth notes):

    /\                                                     
---| /----------------------------------------------------
   |/                                                      
---/---------------*---------*---------*---------*--------
  /|              |         |         |         |         
-/-|/\--------*---|-----*---|-----*---|-----*---|---------
|  |  |      |    |    |    |    |    |    |    |         
|--|--|------|----|----|----|----|----|----|----|---------
 \ |  |      |____|____|____|____|____|____|____|         
--\|_/----------------------------------------------------
   |                                                       
  \|       ff

For*tis"si*mo (? ∨ ?), adv. [It., superl. of forte, adv. See Forte, adv.] Mus.

Very loud; with the utmost strength or loudness.

© Webster 1913.