Facile a.
Etymology: [L. facilis, prop., capable of being done or made, hence, facile, easy, fr. facere to make, do: cf. F. facile. Srr Fact, and cf. Faculty.]
1. Easy to be done or performed: not difficult; performable or attainable with little labor. Order . . . will render the work facile and delightful. Evelyn.
2. Easy to be surmounted or removed; easily conquerable; readily mastered. The facile gates of hell too slightly barred. Milton.
3. Easy of access or converse; mild; courteous; not haughty, austere, or distant; affable; complaisant. I meant she should be courteous, facile, sweet. B. Jonson.
4. Easily persuaded to good or bad; yielding; ductile to a fault; pliant; flexible. Since Adam, and his facile consort Eve, Lost Paradise, deceived by me. Milton. This is treating Burns like a child, a person of so facile a disposition as not to be trusted without a keeper on the king's highway. Prof. Wilson.
1 more senses
5. Ready; quick; expert; as, he is facile in expedients; he wields a facile pen. -- Fac"ile-ly, adv. -- Fac"ile*ness, n.
Shades of meaning
Fernald lists facile only as an antonym, under difficult.
He lists it without comment; the entries above explain its neighbors.