M'ASTERLY, adjective Formed or executed with superior skill; suitable to a master; most excellent; skillful; as a masterly design; a masterly performance; a masterly stroke of policy. 1. Imperious. M'ASTERLY, adverb With the skill of a master. Thou dost speak masterly 'I think it very masterly written, ' in Swift, is improper or unusual.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI