Definition of "hennaed"

Her deeply hennaed hair, almost black at the roots, straggled loosely down both sides of her long face.

1968, Carl Ruhen, The Key Club, Sydney: Scripts, page 12

Lambert's hair is sometimes red, sometimes not, but nowadays it is hennaed and often pinned back with a mother-of-pearl comb.

1988 August 19, Grant Pick, “Where the Action Isn't”, in Chicago Reader‎