ratio

[rey-shoh, -shee-oh] /ˈreɪ ʃoʊ, -ʃiˌoʊ/
noun, plural ratios.
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.
Origin
1630-40; < Latin ratiō a reckoning, account, calculation, derivative (see -tion) of the base of rērī to judge, think

ultima ratio regum

[oo l-ti-mah rah-tee-oh rey-goo m; English uhl-tuh-muh rey-shee-oh ree-guh m] /ˈʊl tɪˌmɑ ˈrɑ tiˌoʊ ˈreɪ gʊm; English ˈʌl tə mə ˈreɪ ʃiˌoʊ ˈri gəm/
Latin.
1.
the final argument of kings (a resort to arms): motto engraved on the cannon of Louis XIV.
Examples from the web for ratio
  • Now, for fuller flavor, she's upped the salsa ratio and uses tomato sauce instead of soup.
  • The match fixes neither distance nor size but only their ratio, as some fraction of a full circle.
  • As the car accelerates, the driver feels no lurch because no step occurs from one ratio to the next.
  • Saving land, particularly rainforest land with its high ratio of endemic animal species, will therefore be required.
  • From the ratio of shoppers to elevators, he might conclude that they were not.
  • Regular jiggering of organic functions is needed to keep the ratio from ballooning to something deadly.
  • The joke-to-apology ratio was skewed toward jokes, and the entire monologue was funny, or intended to be.
  • In plants and animals that eat other life-forms, the isotope ratio should vary widely.
  • Monitor the compost for offensive odors, which indicate an imbalance in the compost ratio.
  • And even these countries often have an unfavorable ratio of water to people.
British Dictionary definitions for ratio

ratio

/ˈreɪʃɪˌəʊ/
noun (pl) -tios
1.
a measure of the relative size of two classes expressible as a proportion: the ratio of boys to girls is 2 to 1
2.
(maths) a quotient of two numbers or quantities See also proportion (sense 6)
Word Origin
C17: from Latin: a reckoning, from rērī to think; see reason
Word Origin and History for ratio
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.

ratio in Medicine

ratio ra·tio (rā'shō, rā'shē-ō')
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.

ratio in Science
ratio
  (rā'shō, rā'shē-ō')   
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.
ratio in Culture
ratio [(ray-shee-oh, ray-shoh)]

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