ratio

 
Pronunciation: /ˈreɪʃɪəʊ/

noun (plural ratios)

  • the quantitative relation between two amounts showing the number of times one value contains or is contained within the other: the ratio of men’s jobs to women’s is 8 to 1

Origin:

mid 17th century: from Latin, literally 'reckoning', from rat- 'reckoned', from the verb reri

Spelling rule

Make the plural of ratio in the usual way, by adding -s: (ratios).