Climb with laces undone (5)
I believe the answer is:
scale
'climb' is the definition.
(scaling is a kind of climbing)
'laces undone' is the wordplay.
'undone' is an anagram indicator.
'laces' anagrammed gives 'SCALE'.
'with' acts as a link.
(Other definitions for scale that I've seen before include "Climb - balance" , "Weigh up" , "Measure" , "Climb, or series of notes in music" , "Deposit formed in a kettle or on teeth" .)