1530s, "overbearing," a sense now obsolete; 1660s, "skillful, skillfully done or performed, with the skill or ability of a master," from master (n.) + -ly. For sense differentiation, see masterful.
a masterly performance of the sonata
massy
mast
mastectomy
master
masterful
masterly
master-mind
masterpiece
master-stroke
master-work
mastery