The Collaborative International Dictionary of English v.0.48:

Cherub \Cher"ub\, n.; pl. Cherubs; but the Hebrew plural
   Cherubimis also used. [Heb. ker[=u]b.]
   1. A mysterious composite being, the winged footstool and
      chariot of the Almighty, described in --Ezekiel i. and x.
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            I knew that they were the cherubim.   --Ezek. x. 20.
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            He rode upon a cherub and did fly.    --Ps. xviii.
                                                  10.
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   2. A symbolical winged figure of unknown form used in
      connection with the mercy seat of the Jewish Ark and
      Temple. --Ez. xxv. 18.
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   3. One of a order of angels, variously represented in art. In
      European painting the cherubim have been shown as blue, to
      denote knowledge, as distinguished from the seraphim (see
      Seraph), and in later art the children's heads with
      wings are generally called cherubs.
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   4. A beautiful child; -- so called because artists have
      represented cherubs as beautiful children.
      [1913 Webster] Cherubic