Volunteers time to make knotted lace (3)
I believe the answer is:
tat
'make knotted lace' is the definition.
(I've seen this before)
'volunteers time' is the wordplay.
'volunteers' becomes 'ta' (abbreviation for Territorial Army).
'time' becomes 't'.
'ta'+'t'='TAT'
'to' acts as a link.
(Other definitions for tat that I've seen before include "Cheap junk" , "Make lace; tasteless stuff" , "Inferior articles" , "Tastelessly ornate things" , "piece of needlework?" .)