Source : WordNet®

nightcrawler
     n : terrestrial worm that burrows into and helps aerate soil;
         often surfaces when the ground is cool or wet; used as
         bait by anglers [syn: {earthworm}, {angleworm}, {fishworm},
          {fishing worm}, {wiggler}, {nightwalker}, {crawler}, {dew
         worm}, {red worm}]