(n): communication by means of written symbols (either printed or handwritten)
(n): mail that includes letters and postcards and packages sealed against inspection
(n): compatibility of observations
(n): capability of existing or performing in harmonious or congenial combination
(n): the relation of corresponding in degree or size or amount
(n): a ratio of two quantities that is constant
(n): (mathematics) an attribute of a shape or relation; exact reflection of form on opposite sides of a dividing line or plane
(n): any property relating to or occupying space
(n): similarity by virtue of corresponding
(n): the quality of being similar
