From The Collaborative International Dictionary of English v.0.48 :
Rocket \Rock"et\, n. [F. roquette (cf. Sp. ruqueta, It
ruchetta), fr. L. eruca.] (Bot.)
(a) A cruciferous plant ({Eruca sativa) sometimes eaten in
Europe as a salad.
(b) Damewort.
(c) Rocket larkspur. See below.
[1913 Webster]
Dyer's Rocket. (Bot.) See Dyer's broom, under Broom.
Rocket larkspur (Bot.), an annual plant with showy flowers
in long racemes ({Delphinium Ajacis).
Sea rocket (Bot.), either of two fleshy cruciferous plants
({Cakile maritima and Cakile Americana) found on the
seashore of Europe and America.
Yellow rocket (Bot.), a common cruciferous weed with yellow
flowers ({Barbarea vulgaris).
[1913 Webster]