currant leaf spot noun : any of three fungous diseases of the currant: a.: an angular leaf spot caused by an imperfect fungus (Cercospora angulata) b.: an anthracnose characterized by small brownish or black spots and caused by a discomycete (Pseudopeziza ribis) c.: a grayish-centered leaf spot caused by an ascomycetous fungus (Mycosphaerella grossulariae)