From The Collaborative International Dictionary of English v.0.48:
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.]
[1913 Webster]
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.
[1913 Webster]
To the nuptial bower
I led her blushing like the morn. --Milton.
[1913 Webster]
In the presence of the shameless and unblushing, the
young offender is ashamed to blush. --Buckminster.
[1913 Webster]
He would stroke
The head of modest and ingenuous worth,
That blushed at its own praise. --Cowper.
[1913 Webster]
2. To grow red; to have a red or rosy color.
[1913 Webster]
The sun of heaven, methought, was loth to set,
But stayed, and made the western welkin blush.
--Shak.
[1913 Webster]
3. To have a warm and delicate color, as some roses and other
flowers.
[1913 Webster]
Full many a flower is born to blush unseen. --T.
Gray.
[1913 Webster]