From Longman Dictionary of Contemporary Englishringwormring‧worm /ˈrɪŋwɜːm $ -wɜːrm/ noun [uncountable] MIa skin infection that causes red rings, especially on your head
Examples from the Corpus
ringworm• It may also appear on other parts of the body in the form of an itchy rash known as ringworm.• Her services were also called upon to charm away warts and cure ringworm in cattle.• A litany of nits, ringworm, fleas and unmentionables ... But as the weeks and months passed, everything changed.• She gave the money for the words not used to a boy with ringworm throwing stones at a cat on a wall. 