The Collaborative International Dictionary of English v.0.48:

aloe \al"oe\ ([a^]l"n[-o]), n.; pl. Aloes ([a^]l"[=o]z). [L.
   alo["e], Gr. 'alo`h, aloe: cf. OF. aloe, F. alo[`e]s.]
   1. pl. The wood of the agalloch. [Obs.] --Wyclif.
      [1913 Webster]

   2. (Bot.) [capitalized] A genus of succulent plants, some
      classed as trees, others as shrubs, but the greater number
      having the habit and appearance of evergreen herbaceous
      plants; from some of which are prepared articles for
      medicine and the arts. They are natives of warm countries.
      [1913 Webster]

   3. pl. (Med.) The inspissated juice of several species of
      aloe, used as a purgative. [Plural in form but
      syntactically singular.] AS
      [1913 Webster]

   American aloe, Century aloe, the agave. See Agave.
      [1913 Webster]

WordNet (r) 3.0 (2006):

American aloe
    n 1: tropical American plants with basal rosettes of fibrous
         sword-shaped leaves and flowers in tall spikes; some
         cultivated for ornament or for fiber [syn: agave,
         century plant, American aloe]