Source : Webster's Revised Unabridged Dictionary (1913)

Blush \Blush\ (bl[u^]sh) v. i. [imp. & p. p. {Blushed}
   (bl[u^]sht); p. pr. & vb. n. {Blushing}.] [OE. bluschen to
   shine, look, turn red, AS. blyscan to glow; akin to blysa a
   torch, [=a]bl[=y]sian to blush, D. blozen, Dan. blusse to
   blaze, blush.]
   1. To become suffused with red in the cheeks, as from a sense
      of shame, modesty, or confusion; to become red from such
      cause, as the cheeks or face.

            To the nuptial bower I led her blushing like the
            morn.                                 --Milton.

            In the presence of the shameless and unblushing, the
            young offender is ashamed to blush.   --Buckminster.

            He would stroke The head of modest and ingenuous
            worth, That blushed at its own praise. --Cowper.

   2. To grow red; to have a red or rosy color.

            The sun of heaven, methought, was loth to set, But
            stayed, and made the western welkin blush. --Shak.

   3. To have a warm and delicate color, as some roses and other
      flowers.

            Full many a flower is born to blush unseen. --T.
                                                  Gray.

Blushing \Blush"ing\, a.
   Showing blushes; rosy red; having a warm and delicate color
   like some roses and other flowers; blooming; ruddy; roseate.

         The dappled pink and blushing rose.      --Prior.

Blushing \Blush"ing\, n.
   The act of turning red; the appearance of a reddish color or
   flush upon the cheeks.

Source : WordNet®

blushing
     adj : having a red face from embarrassment or shame or agitation
           or emotional upset; "the blushing boy was brought
           before the Principal"; "her blushful beau"; "was
           red-faced with anger" [syn: {blushful}, {blushing(a)},
           {red-faced}]