ad ‧ dict /ˈædɪkt/ BrE AmE noun [countable]
[ Date: 1500-1600 ; Language: Latin ; Origin: past participle of addicere 'to give to formally or legally' , from ad- 'to' + dicere 'to say' ]
1 . someone who is unable to stop taking drugs
drug/heroin/morphine etc addict
a recovering heroin addict
2 . someone who is very interested in something and spends a lot of time doing it
TV/sports etc addict
My nephew is a complete video game addict.