The Collaborative International Dictionary of English v.0.48:

Lima \Li"ma\ (l[=e]"m[.a] or l[imac]"m[.a]), n.
   The capital city of Peru, in South America.
   [1913 Webster]

   Lima bean. (Bot.)
   (a) A variety of climbing or pole bean (Phaseolus lunatus),
       which has very large flattish seeds.
   (b) The seed of this plant, much used for food.

   Lima wood (Bot.), the beautiful dark wood of the South
      American tree C[ae]salpinia echinata.
      [1913 Webster]

WordNet (r) 3.0 (2006):

lima bean
    n 1: bush bean plant cultivated especially in southern United
         States having small flat edible seeds [syn: sieva bean,
         butter bean, butter-bean plant, lima bean, Phaseolus
         lunatus]
    2: bush or tall-growing bean plant having large flat edible
       seeds [syn: lima bean, lima bean plant, Phaseolus
       limensis]
    3: broad flat beans simmered gently; never eaten raw