Ordeal of equipment belonging to us (6)
I believe the answer is:
rigour
'ordeal' is the definition.
'equipment belonging to us' is the wordplay.
'equipment' becomes 'rig' (rig is a kind of equipment).
'belonging to us' becomes 'our' (us, you and me).
'rig'+'our'='RIGOUR'
'of' acts as a link.
(Other definitions for rigour that I've seen before include "Extreme strictness" , "Sternness" , "Strict precision, of thought say" , "Preciseness - severity" , "Extreme care and thoroughness" .)