say it: MAHY-luhj
mileage is a noun meaning "distance measured in miles". It carries 3 recorded senses.
the ratio of the number of miles traveled to the number of gallons of gasoline burned
a travel allowance at a given rate per mile traveled
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for mileage come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.