1. Break or interruption in music, notated by two diagonal lines often refered to as railroad tracks. The break can be of any length at the discretion of the conductor.
2. In prosody, a break in the flow of sound in the middle of a line of verse often caused by the ending of a word within a foot.

Also [Fr.] césure or pauses; [Ger.] Cäsur or Zäsur; [It.] pause or cesura; [Sp.] cesura.