In the title compound, C(22)H(17)NO(2), the acridine ring system and the benzene ring are oriented at a dihedral angle of 37.7 (1)°. The carboxyl group is twisted at an angle of 67.7 (1)° relative to the acridine skeleton. In the crystal, mol-ecules are arranged in stacks along the b axis, with all of the acridine rings involved in multiple π-π inter-actions [centroid-centroid distances in the range 3.632 (2)-4.101 (2) Å]. The acridine moieties are parallel within the stacks, but inclined at an angle of 52.7 (1)° in adjacent stacks.