der ‧ ma ‧ tol ‧ o ‧ gy /ˌdɜːməˈtɒlədʒi $ ˌdɜːrməˈtɑː-/ BrE AmE noun [uncountable]
[ Date: 1800-1900 ; Language: Greek ; Origin: derma 'skin' ]
the part of medical science that deals with skin diseases and their treatment
—dermatologist noun [countable]