Nowadays the opening is loose (6)
I believe the answer is:
adrift
'is loose' is the definition.
(I've seen this before)
'nowadays the opening' is the wordplay.
'nowadays' becomes 'AD' (AD, Anno Domini, as opposed to BC, Before Christ).
'the opening' becomes 'rift' (rift is a kind of opening).
'ad'+'rift'='ADRIFT'
(Other definitions for adrift that I've seen before include "Floating uncontrolled" , "Unsettled or unanchored" , "Moving aimlessly, unfastened" , "out of touch" , "Wandering aimlessly" .)