del ‧ e ‧ ter ‧ i ‧ ous /ˌdeləˈtɪəriəs◂, ˌdelɪˈtɪəriəs◂ $ -ˈtɪr-/ BrE AmE adjective formal
[ Date: 1600-1700 ; Language: Medieval Latin ; Origin: deleterius , from Greek deleisthai 'to hurt' ]
damaging or harmful SYN detrimental :
the deleterious effects of smoking