From BiblePortal Wikipedia

Webster's Dictionary [1]

(1): ( a.) Discerning; reasonable; judicious; cunning.

(2): ( a.) Possessed of, or displaying, skill; knowing and ready; expert; well-versed; able in management; as, a skillful mechanic; - often followed by at, in, or of; as, skillful at the organ; skillful in drawing.

King James Dictionary [2]

Skill'Ful, a.

1. Knowing well versed in any art hence, dextrous able in management able to perform nicely any manual operation in the arts or professions as a skillful mechanic a skillful operator in surgery. 2. Well versed in practice as a skillful physician.

It is followed by at or in as skillful at the organ skillful in drawing.