Small print run (6)

I believe the answer is:

sprint

'run' is the definition.
(sprinting is a kind of running)

'small print' is the wordplay.
'small' becomes 's' (abbreviation - e.g. clothes size).
's'+'print'='SPRINT'

(Other definitions for sprint that I've seen before include "quick run" , "Run rapidly" , "Quick dash" , "To make fast progress" , "Run quickly" .)

I've seen this clue in The Times.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.