From Longman Dictionary of Contemporary Englishreddenred‧den /ˈredn/ verb [intransitive, transitive] written CCEMBARRASSEDto become red, or to make something red Sue’s face reddened.→ See Verb table
Examples from the Corpus
redden• I went very hot and felt myself redden.• In a moment they reddened and flared up, and before long the water was bubbling.• Beatrice Varney reddened and glanced at her daughter.• My friend's face was reddened by her red coat.• His ankles are reddened by sand-flea bites, his head has been shorn to indicate his reduction in status.• I must have reddened, I sensed my ears burning bright.• Her face reddened in embarrassment.• I doubt very much that your wrist is even slightly reddened, let alone broken.