ˈdär.ˌtrōs also -ōz noun
( -s )
Etymology: French, from dartre herpes, tetter (from Middle French dertre, from Latin derbita, of Celtic origin; akin to Middle Breton dervoeden herpes, Welsh darwden, tarwden ringworm) + -ose; akin to Old English teter tetter, Old High German zittaroh herpes, tetter, Sanskrit dadru, a kind of leprosy, skin eruption, Old English teran to tear — more at tear
: a disease of the potato and tomato caused by a fungus ( Colletotrichum atramentarium ) and characterized by destruction of the stems especially towards the base, by yellowing and drying of the foliage, and by development of numerous small black sclerotia in the diseased stem tissue — called also black dot, black speck