Lose current agent destroyed after attempt that’s lost billions (8)
I believe the answer is:
stagnate
'lose current' is the definition.
(to stagnate is to cease to flow)
'agent destroyed after attempt that's lost billions' is the wordplay.
I cannot quite see how this works, but
an anagram of 'agent' is 'gnate' which is present in the answer.
The remaining letters 'sta' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for stagnate that I've seen before include "Cease motion" , "Become inactive (and malodorous)" , "Tan gates could vegetate" , "Cease activity" , "Cease to flow or move" .)