(automotive) The ratio of the volume between the cylinder head of an internal combustion engine and the piston before and after the compression stroke

(measurement, statistics) A scale of measurement of data having a fixed zero value, which permits the quantitative comparison of differences of values.

(physics, mathematics) A dimensionless measure of the damping in second-order linear dynamic system, appearing as the term 𝜁 in the generalised equation of motion for such a system, ̈q+2𝜁𝜔ₙ̇q+𝜔ₙ²q=F.

(geography) The number of people under the age of 15 and over the age of 64 compared to the number of people active in the labor force.

(chemistry) The ratio of the percent of one enantiomer in a mixture to that of the other

(finance) A ratio that measures the excess return (or risk premium) per unit of deviation in an investment asset or a trading strategy, used to examine the performance of an investment by adjusting for its risk.

(poker) A measure of the health of one's stack: the stack divided by the sum of the small blind, the big blind and the antes of each player. The result (M) is the time (the number of orbits) it would take for one's chips to deplete if the player only passively places their forced bets and otherwise folds.

plural of ratio scale

(philosophy, logic) the formal grounds for something; the essential attributes of matter as they appear in the mind or in a definition.

(statistics) A variable with the features of interval variable and, additionally, whose any two values have meaningful ratio, making the operations of multiplication and division meaningful.