A dark purple variety of plum; the tree bearing this fruit, used chiefly as a stock for grafting.
Origin
Early 17th century; earliest use found in Francis Bacon (1561–1626), lord chancellor, politician, and philosopher. From mussel + plum, so named from its resemblance in shape and colour to a mussel shell.
Definition of mussel plum in US English:
mussel plum
nounˈmʌsl plʌm
A dark purple variety of plum; the tree bearing this fruit, used chiefly as a stock for grafting.
Origin
Early 17th century; earliest use found in Francis Bacon (1561–1626), lord chancellor, politician, and philosopher. From mussel + plum, so named from its resemblance in shape and colour to a mussel shell.