blush

(noun) a rosy color (especially in the cheeks) taken as a sign of good health. Synonyms: bloom, flush, rosiness.

(noun) sudden reddening of the face (as from embarrassment or guilt or shame or modesty). Synonyms: flush.

(verb) turn red, as if in embarrassment or shame. Synonyms: crimson, flush, redden. Example: "The girl blushed when a young man whistled as she walked by."

(verb) become rosy or reddish. Example: "Her cheeks blushed in the cold winter air."