The Collaborative International Dictionary of English v.0.48:

Ramson \Ram"son\ (r[a^]m"z'n), n. [AS. hramsan, pl., akin to G.
   rams, Sw. rams, ramsl["o]k; cf. Gr. kro`myon onion.] (Bot.)
   A broad-leaved species of garlic (Allium ursinum), common
   in European gardens; -- called also buckram.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Allium ursinum
    n 1: pungent Old World weedy plant [syn: wild garlic, wood
         garlic, Ramsons, Allium ursinum]