gooseberry -
n. (pl. -ies)
1 a round edible yellowish-green
berry with a thin usu. translucent skin enclosing seeds in a juicy flesh.
2 the thorny shrub, Ribes grossularia, bearing this fruit.
play gooseberry Brit. colloq. be an unwanted extra (usu. third) person. [perh. f. GOOSE + BERRY]