Definitions of leash:

• noun:   restraint consisting of a rope (or light chain) used to restrain an animal
• noun:   a figurative restraint

  Example: "Kept a tight leash on his emotions"

• noun:   the cardinal number that is the sum of one and one and one
• verb:   fasten with a rope
• name:  A surname (very rare: popularity rank in the U.S.: #82188)