Definition of "henna"

(countable) A shrub, Lawsonia inermis, having fragrant reddish flowers  examples

(countable, uncountable) 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.  examples

(countable and uncountable) A rich reddish-brown colour.  examples

Of a rich reddish-brown colour.  examples

(transitive) To dye or tattoo with henna.  examples