One bent on giving up measure of dress material (4-6)
I believe the answer is:
knee-length
'dress material' is the definition.
The definition suggests an adjective which matches the answer.
'one bent on giving up measure' is the wordplay.
I cannot really see how this works, but
'measure' could be 'length' (length is a kind of measure) and 'length' is found in the answer.
The remaining letters 'knee' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
'of' is the link.
Can you help me to learn more?
(Another definition for knee-length that I've seen is " Like some breeches".)