Definitions of rack:

• noun:   a rapid gait of a horse in which each foot strikes the ground separately
• noun:   a support for displaying various articles

  Example: "The newspapers were arranged on a rack"

• noun:   framework for holding objects
• noun:   an instrument of torture that stretches or disjoints or mutilates victims
• noun:   rib section of a forequarter of veal or pork or especially lamb or mutton
• noun:   the destruction or collapse of something

  Example: "Wrack and ruin"

• verb:   put on a rack and pinion

  Example: "Rack a camera"

• verb:   torture on the rack
• verb:   seize together, as of parallel ropes of a tackle in order to prevent running through the block
• verb:   work on a rack

  Example: "Rack leather"

• verb:   stretch to the limits

  Example: "Rack one's brains"

• verb:   draw off from the lees

  Example: "Rack wine"

• verb:   fly in high wind
• verb:   run before a gale
• verb:   go at a rack
• verb:   obtain by coercion or intimidation
• verb:   torment emotionally or mentally
• name:  A surname (very rare: popularity rank in the U.S.: #42421)