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gradability

American  
[grey-duh-bil-i-tee] / ˌgreɪ dəˈbɪl ɪ ti /
Or gradeability

noun

Transportation.
  1. a measure of a truck's pulling power expressed as the steepest grade the truck can climb with a full load.


Etymology

Origin of gradability

First recorded in 1950–55; grade + -ability