know–it–all 
/ˈnowətˌɑ:l/ noun
plural know–it–alls /ˈnowətˌɑ:l/ noun [count] informal + disapproving : a person who talks and behaves like someone who knows everything
▪ My neighbor is a real know-it-all, always telling me what to do. — often used before another noun ▪ my know-it-all neighbor —called also (Brit) know-all
▪ My neighbor is a real know-it-all, always telling me what to do. — often used before another noun ▪ my know-it-all neighbor —called also (Brit) know-all
