The Collaborative International Dictionary of English v.0.48:

Crambo \Cram"bo\ (-b[-o]), n. [Cf. Cramp, a., difficult.]
   1. A game in which one person gives a word, to which another
      finds a rhyme.
      [1913 Webster]

            I saw in one corner . . . a cluster of men and
            women, diverting themselves with a game at crambo. I
            heard several double rhymes . . . which raised a
            great deal of mirth.                  --Addison.
      [1913 Webster]

   2. A word rhyming with another word.
      [1913 Webster]

            His similes in order set
            And every crambo he could get.        --Swift.
      [1913 Webster]

   Dumb crambo, a game in which one party of players give a
      word which rhymes with another, which last to be guessed
      by the opposing party, who represent in dumb show what
      they think it to be.
      [1913 Webster]