any component part of the departure from uniformity in astronomical phenomena, especially in orbital motion.
b.
the amount of such a departure.
9.
Mathematics. a statement that two quantities are unequal, indicated by the symbol ≠; alternatively, by the symbol <, signifying that the quantity preceding the symbol is less than that following, or by the symbol >, signifying that the quantity preceding the symbol is greater than that following.
1484, "difference of rank or dignity," from O.Fr. inequalité (14c.), from M.L. inæqualitas, from inæqualis "unequal," from in- "not" + æqualis "equal" (see equal).