Definitions of stiff:

• noun:   an ordinary man

  Example: "A lucky stiff"

• noun:   the dead body of a human being
• adjective:   not moving or operating freely

  Example: "A stiff hinge"

• adjective:   powerful

  Example: "A stiff current"

• adjective:   lacking ease in bending; not limber

  Example: "A stiff neck"

• adjective:   hard to overcome or surmount

  Example: "A stiff hike"

• adjective:   incapable of or resistant to bending

  Example: "A palace guardsman stiff as a poker"

• adjective:   of a collar; standing up rather than folded down

  Example: "A stiff collar"

• adjective:   rigidly formal

  Example: "The letter was stiff and formal"

• adjective:   very drunk
• adverb:   extremely

  Example: "Bored stiff"

• adverb:   in a stiff manner

  Example: "His hands lay stiffly"

• name:  A surname (rare: 1 in 100000 families; popularity rank in the U.S.: #11622)