Synonyms for Easiness:

n.

effortlessness, facileness, easy. spontaneity, unrestraint, poise, naturalness, unceremoniousness, tighten, casualness. carelessness (noun)
carelessness, ability, ease, nonchalance.
easiness (noun)
relaxation, simplicity, ease.
feeling (noun)
relaxation.
mildness (noun)
laxity, meekness, charity, moderateness, benignity, liberty, cordiality, evenness, geniality, tolerance, libertarianism, quietness, benevolence, insipidity, latitude, permissiveness, liberalness, broad-mindedness, lenience, mildness, peaceableness, moderation, acceptance, amiability, gentleness, tenderness, forbearance, open-mindedness, liberality, kindness, clemency, softness.
simplicity (noun)
simplicity.

Other synonyms:

facileness, effortlessness, casualness, unceremoniousness, naturalness. unrestraint, spontaneity. poise. Other relevant words:
nonchalance, tighten, easy, carelessness, ability, unceremoniousness, ease, naturalness, spontaneity, relaxation, unrestraint, casualness, simplicity, poise, effortlessness, facileness.

Usage examples for easiness

  1. It was Hannibal's chance to be staying here, and having ever from the beginning had a distrust of the easiness and cowardice of Prusias, and a fear of the Romans, he had, long before, ordered seven underground passages to be dug from his house, leading from his lodging, and running a considerable distance in various opposite directions, all undiscernible from without. – Plutarch-Lives-of-the-noble-Grecians-and-Romans by Clough, Arthur Hugh
  2. 3. Easiness of access, without passing through the house. – The Book of Household Management by Mrs. Isabella Beeton
  3. All life may flash into beauty, and tower into greatness, and be smoothed out into easiness and the crooked things may be made straight and the rough places plain, and the familiar and the trite be invested with freshness and wonder as of a dream, if only we write over them, 'For the sake of the Master. – Expositions of Holy Scripture: Romans Corinthians (To II Corinthians, Chap. V) by Alexander Maclaren