There are two independent molecules (A and B) in the asymmetric unit of the title compound, C19H23NOS. In each molecule, the seven-membered thiepine ring is bent into a slightly twisted V-shape. The dihedral angles between the mean planes of the two benzene rings fused to the thiepine ring are 75.7 (5) in molecule A and 73.8 (4)° in molecule B. In both molecules, an intramolecular O—H⋯N hydrogen bond occurs. In the crystal, weak intermolecular C—H⋯O and C—H⋯π-ring interactions are observed.