henna

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A tree or shrub (Lawsonia inermis) of the Middle East, having fragrant white or reddish flowers.
2. n. A reddish-orange dyestuff prepared from the dried and ground leaves of this plant, used as a cosmetic dye and for coloring leather and fabrics.
3. n. A moderate or strong reddish brown to strong brown.
4. v. To dye (hair, for example) with henna.

Century Dictionary and Cyclopedia

1. n. The Egyptian privet or flower of Paradise, Lawsonia inermis, of the natural order Lythrarieœ, a shrub bearing opposite entire leaves and numerous small and fragrant white flowers. It was called by Mohammed “chief of the flowers of this world and the next.” It is cultivated extensively in Egypt. The powdered leaves form a large article of export to Persia and the Turkish possessions, where they are used as a dye, and in the form of a paste as a cosmetic. (See def. 2.) They produce a reddish-brown color, and in Europe are employed in dyeing leather. Henna is considered the best hedge-plant in India.
2. n. A paste made from the leaves of this plant by mixture with catechu, used in the East by women to stain their nails, finger-tips, and eyelids. and by men to dye their beards. The reddish-orange color it imparts is not permanent. It is often deepened to black by the addition of other ingredients.

Wiktionary

1. n. A shrub, Lawsonia inernis, having fragrant redish flowers
2. n. A reddish plant substance, prepared from the dried leaves of this plant, used for temporary tattoos and hair coloring. Hair colorings range from bright red to earth brown to near black.
3. n. a rich reddish-brown colour.
4. adj. of a rich reddish-brown colour.

GNU Webster's 1913

1. n. A thorny tree or shrub of the genus Lawsonia (Lawsonia alba). The fragrant white blossoms are used by the Buddhists in religious ceremonies. The powdered leaves furnish a red coloring matter used in the East to stain the nails and fingers, the manes of horses, etc.
2. n. The leaves of the henna plant, or a preparation or dyestuff made from them.

WordNet 3.0

1. v. apply henna to one's hair
2. n. a reddish brown dye used especially on hair