The Collaborative International Dictionary of English v.0.48:

Areca \A*re"ca\, n. [Canarese adiki: cf. Pg. & Sp. areca.]
   (Bot.)
   A genus of palms, one species of which (Areca catechu)
   produces the areca nut, or betel nut, which is chewed in
   India and Southeast Asia with the leaf of the Piper Betle
   and lime.
   [1913 Webster +PJC]

The Collaborative International Dictionary of English v.0.48:

Betel \Be"tel\ (b[=e]"t'l), n. [Pg., fr. Tamil ve[.t][.t]ilei,
   prop. meaning, a mere leaf.] (Bot.)
   A species of pepper (Piper betle), the leaves of which are
   chewed, with the areca or betel nut and a little shell lime,
   by the inhabitants of the East Indies. It is a woody climber
   with ovate many-nerved leaves.
   [1913 Webster]