# ratio noun, plural ra·tios.

1. the relation between two similar magnitudes with respect to the number of times the first contains the second: the ratio of 5 to 2, written 5:2 or 5/2.
2. proportional relation; rate: the ratio between acceptances and rejections.
3. Finance. the relative value of gold and silver in a bimetallic currency system.

Latin.

1. the final argument of kings (a resort to arms): motto engraved on the cannon of Louis XIV.

noun plural -tios

1. a measure of the relative size of two classes expressible as a proportionthe ratio of boys to girls is 2 to 1
2. maths a quotient of two numbers or quantitiesSee also proportion (def. 6)
n.

1630s, “reason, rationale,” from Latin ratio “reckoning, numbering, calculation; business affair, procedure,” also “reason, reasoning, judgment, understanding,” from rat-, past participle stem of reri “to reckon, calculate,” also “think” (see reason (n.)). Mathematical sense “relationship between two numbers” is attested from 1650s.

n. pl. ra•tios

1. Relation in degree or number between two similar things.
2. The relation between two quantities expressed as the quotient of one divided by the other.

1. A relationship between two quantities, normally expressed as the quotient of one divided by the other. For example, if a box contains six red marbles and four blue marbles, the ratio of red marbles to blue marbles is 6 to 4, also written 6:4. A ratio can also be expressed as a decimal or percentage.

An expression of the relative size of two numbers by showing one divided by the other. 45 queries 1.322