noun

• (figuratively) A feeling or appearance of optimism.
  "1974, “April's Fading Carnation,” Time, 9 September, 1974,https://web.archive.org/web/20130813201436/http://www.time.com/time/magazine/article/0,9171,904100,00.html The independence ceremony could not keep the blush of April's revolution, when carnations had seemed to sprout from every buttonhole, from fading."
• (uncountable, countable) A sort of makeup, frequently a powder, used to redden the cheeks.
  "The same rules that apply to face powder apply to powder blush, since neither contains water. Cream blush, however, should be replaced after a year. To prolong the life of any blush, clean your blush brush regularly and store the product in a dry place."
• (chiefly US) A pale pink wine made by removing the dark grape skins at the required point during fermentation.
  "2016, Mishkah Abrahams, “Blush or Rosé? The Cape's Best Summer Drink,” capetownetc.com, 29 September, 2016, If you’re looking to indulge in some good food while you sip your blush, pair the Chardonnay-Pinot Noir with fresh, summer foods such as sushi, refreshing salads, delicious seafood and fruity summertime desserts."

verb

• (intransitive) To become red or pink in the face (and sometimes experience an associated feeling of warmth), especially due to shyness, love, shame, excitement, or embarrassment.
  "The love scene made him blush to the roots of his hair / to the tips of his ears."
• (intransitive, figuratively) To be shy, ashamed, or embarrassed (to do something).
  "While Cato lives, Caesar will blush to see Mankind enslaved, and be ashamed of Empire."
• (intransitive) To become red or pink.
  "The sun of heaven, methought, was loth to set, But stayed, and made the western welkin blush,"
• (transitive) To suffuse with a blush; to redden; to pinken; to make rosy.
  "[the ghost] with the heart there cools and ne’er returneth To blush and beautify the cheek again."