Disparity, n.; pl. Disparities.
Etymology: [LL. disparitas, fr. L. dispar unlike, unequal; dis- + par equal: cf. F. disparité. See Par, Peer.]
Inequality; difference in age, rank, condition, or excellence; dissimilitude; -- followed by between, in, of, as to, etc.; as, disparity in, or of, years; a disparity as to color. The disparity between God and his intelligent creatures. I. Taylor. The disparity of numbers was not such as ought to cause any uneasiness. Macaulay.
Syn. -- Inequality; unlikeness; dissimilitude; disproportion; difference.
Shades of meaning
Fernald has no entry of its own for disparity; he lists it under difference.
Where he writes about it:
Disparity is stronger than inequality, implying that one thing falls far below another; as, the disparity of our achievements when compared with our ideals. — from difference