Tread a measure? (4)
I believe the answer is:
step
I believe this clue is a double definition.
'tread' is the first definition.
('step' can be a synonym of 'tread')
'a measure?' is the second definition.
(step is a kind of measure)
(Other definitions for step that I've seen before include "Place foot on as with a pest" , "Footfall" , "Movement in dancing" , "little walk?" , "Rung, dance movement" .)