Tire's groove pattern (5)
I believe the answer is:
tread
'tire's groove pattern' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for tread that I've seen before include "dance" , "March" , "Depth of grooving in a tyre" , "Moulded part of a tyre" , "Walk; part of tyre" .)