What is "hagberry"

Hagberry \Hag"ber`ry\ (h[a^]g"b[e^]r`r[y^]), n. (Bot.) A plant of the genus Prunus ( Prunus Padus); the bird cherry. [Scot.]

n. 1 ''Prunus padus'', a species of cherry native to northern Europe and northern Asia, the bird cherry. 2 Its bittersweet astringent fruit, readily eaten by birds and Russians.

n. small cherry much liked by birds