From Longman Dictionary of Contemporary Englishdiaper rashˈdiaper ˌrash noun [uncountable] MIDHB American English sore skin between a baby’s legs and on its buttocks, caused by a wet diaper SYN nappy rash British English
Examples from the Corpus
diaper rash• The Olympians are swabbing their faces with Desitin, the white goop generally used to combat diaper rash.• At least half of all infants get diaper rash at some time during their diaper careers.• I saw one of the hardiest women I know burst into tears of self-loathing because her daughter had diaper rash.• The baby never has colic, thrush, diaper rash, infant acne, or cradle cap. 