a. Bot. [f. L. ACANTH-US + -ACEOUS.] Of the type of the Acanthus; epithet of the natural order Acanthaceæ, of which the Acanthus is the typical genus.
1751. Chambers, Cycl., s.v. Acanthus, Acanthus … the representation of the leaves of an acanthaceous plant.
1880. J. S. Cooper, Coral Lands, I. xvii. 197. An acanthaceous herb, inhabiting swamps.
