yaws
Concise Oxford English Dictionary © 2008 Oxford University Press:
yaws/jɔːz/
▶plural noun [treated as sing.] a contagious tropical disease caused by a bacterium that enters skin abrasions and causes small crusted lesions which may develop into deep ulcers.
– origin C17: prob. from Carib yaya.
'yaws' also found in these Oxford entries:

