Luffa \Luf"fa\, n. [NL., fr. Ar. l[=u]fah.]

(Bot.)
   (a) A small genus of tropical cucurbitaceous plants having white flowers, the staminate borne in racemes, and large fruits with a dry fibrous pericarp. The fruit of several species and the species themselves, esp. L. [AE]gyptiaca, are called dishcloth gourds.
   (b) Any plant of this genus, or its fruit.
   (c) The fibrous skeleton of the fruit, used as a sponge and in the manufacture of caps and women's hats; -- written also loofah.

Source: Webster's Revised Unabridged Dictionary (1913)