Reddenings refer to any redness or inflammation on the skin or any surface. Some common synonyms for reddening include blushing, flushing, ruddiness, roseate, crimson, fiery, pinkish, and scarlet. Other synonyms for reddening can be blood rushing, heat surging, skin flushing, and blushing with shyness or embarrassment. The word reddening is often used to describe a physiological response to a stimulus, such as a slap or a sudden rush of blood to the face. Regardless of the cause, reddening is an indication of heightened blood flow, which can be neutral or positive, depending on the context.