ex ‧ cres ‧ cence /ɪkˈskres ə ns/ BrE AmE noun [countable] formal
[ Date: 1400-1500 ; Language: Latin ; Origin: excrescens , present participle of excrescere 'to grow out' , from crescere 'to grow' ]
1 . something that is bad, unnecessary, or ugly – used to show disapproval:
The new museum is nothing but an excrescence on the urban landscape.
2 . an ugly growth on an animal or plant