Material I mend ingeniously (5)
I believe the answer is:
denim
'material' is the definition.
(type of fabric)
'i mend ingeniously' is the wordplay.
'ingeniously' is an anagram indicator (I've seen this in other clues).
'i'+'mend'='imend'
'imend' anagrammed gives 'DENIM'.
(Other definitions for denim that I've seen before include "Tough cotton fabric" , "Thick cotton cloth" , "Fabric used for jeans" , "Cloth for jeans, etc" , "Durable material" .)