masterly
Masterly (adj) means Done with great skill, showing the ability of an expert.
Etymology
The word goes back to the Proto-Indo-European word *méǵh₂s. It comes from Middle English maisterli, from maister (“leader, ruler; high official; official in charge of a place; person in control; employer; owner; schoolmaster, teacher; scholar, sage; holder of a master's degree; religious teacher; master craftsman; expert; magician; social superior; husband; lover; Jesus Christ; a god; male stud animal”) plus -li (suffix forming adjectives). Maister in turn derives from Old English mæġester (“master”) and Old French maistre (“master”) (modern French maître), both going back to Latin magister (“teacher; master”), and ultimately to Proto-Indo-European *méǵh₂s (“big, great”). By surface analysis the English word breaks down as master + -ly.