The Collaborative International Dictionary of English v.0.48:

Sundew \Sun"dew`\, n. (Bot.)
   Any plant of the genus Drosera, low bog plants whose leaves
   are beset with pediceled glands which secrete a viscid fluid
   that glitters like dewdrops and attracts and detains insects.
   After an insect is caught, the glands curve inward like
   tentacles and the leaf digests it. Called also lustwort.
   [1913 Webster]

WordNet (r) 3.0 (2006):

sundew
    n 1: any of various bog plants of the genus Drosera having
         leaves covered with sticky hairs that trap and digest
         insects; cosmopolitan in distribution [syn: sundew,
         sundew plant, daily dew]