The Collaborative International Dictionary of English v.0.48:

Tuberose \Tube"rose`\, n. [Cf. G. tuberose, F. tub['e]reuse, NL.
   Polianthes tuberosa. See Tuberous.] (Bot.)
   A plant (Polianthes tuberosa) with a tuberous root and a
   liliaceous flower. It is much cultivated for its beautiful
   and fragrant white blossoms.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Polianthes tuberosa
    n 1: a tuberous Mexican herb having grasslike leaves and
         cultivated for its spikes of highly fragrant lily-like waxy
         white flowers [syn: tuberose, Polianthes tuberosa]