(grammar) the superlative (a degree of comparison) when it is used to express the highest degree of something in relation to something else

(sciences) A measure of the density of a material. The ratio of the density of a substance to the density of water at the same temperature. It is dimensionless and therefore has no units.

(grammar) A subordinate clause that modifies a noun.

(relativity) A theory that (neglecting the effects of gravity) reconciles the principle of relativity with the observation that the speed of light is constant in all frames of reference.

(relativity) A theory extending special relativity and uniformly accounting for gravity and accelerated frames of reference, postulating that space-time curves in the presence of mass.

(relativity) The principle that only the motion of objects relative to one another can be measured, and that there is no absolute frame of reference.

(meteorology) The ratio of the actual amount of water vapor (absolute humidity) present in the air to the saturation point at the same temperature, usually expressed as a percentage.

(statistics) The number of data points satisfying something divided by the total number of data points.

plural of non-relative

plural of theory of relativity