The Collaborative International Dictionary of English v.0.48:

Mirabilis \Mi*rab"i*lis\, prop. n. [L., wonderful.] (Bot.)
   A genus of plants. See Four-o'clock.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Mirabilis
    n 1: four o'clocks [syn: Mirabilis, genus Mirabilis]