Source : Webster's Revised Unabridged Dictionary (1913)

Radish \Rad"ish\, n. [F. radis; cf. It. radice, Pr. raditz: all
   fr. L. radix, -icis, a root, an edible root, especially a
   radish, akin to E. wort. See {Wort}, and cf. {Eradicate},
   {Race} a root, {Radix}.] (Bot.)
   The pungent fleshy root of a well-known cruciferous plant
   ({Paphanus sativus}); also, the whole plant.

   {Radish fly} (Zo["o]l.), a small two-winged fly ({Anthomyia
      raphani}) whose larv[ae] burrow in radishes. It resembles
      the onion fly.

   {Rat-tailed radish} (Bot.), an herb ({Raphanus caudatus})
      having a long, slender pod, which is sometimes eaten.

   {Wild radish} (Bot.), the jointed charlock.

Source : WordNet®

radish
     n 1: pungent fleshy edible root
     2: pungent edible root of any of various cultivated radish
        plants
     3: Eurasian plant widely cultivated for its edible pungent root
        usually eaten raw [syn: {Raphanus sativus}]