m vs metre

m

verb

  • make 

character

  • The thirteenth letter of the English alphabet, called em and written in the Latin script. 

metre

verb

  • To put into metrical form. 

noun

  • The basic unit of length in the International System of Units (SI: Système International d'Unités), equal to the distance travelled by light in a vacuum in 1/299 792 458 seconds. The metre is equal to 39+⁴⁷⁄₁₂₇ (approximately 39.37) imperial inches. 

  • The rhythm or measure in verse and musical composition. 

How often have the words m and metre occurred in a corpus of books? (source: Google Ngram Viewer )