Second-hand thought to lose minutes (4)
I believe the answer is:
used
'second-hand' is the definition.
(I've seen this before)
'thought to lose minutes' is the wordplay.
'thought' becomes 'mused' (musing is a kind of thinking).
'to lose' suggests deleting specific letters.
'minutes' becomes 'm' (common abbreviation).
'mused' with 'm' taken out is 'USED'.
(Other definitions for used that I've seen before include "Employed - exploited" , "Exploited - not new" , "Scottish expert" , "Accustomed, having been put into service" , "Sued, having been employed" .)