Placed informants over in newly opened business (7)
I believe the answer is:
startup
'newly opened business' is the definition.
'startup' can be an answer for 'business' (I have seen 'new business' mean 'startup' so perhaps 'business' could also mean 'startup'). I'm unsure of the 'newly opened' bit.
'placed informants over' is the wordplay.
'placed' becomes 'put' (I've seen this before).
'informants' becomes 'rats' (rat is a kind of informant).
'over' says the letters should be written in reverse.
'put'+'rats'='putrats'
'putrats' reversed gives 'STARTUP'.
'in' is the link.
Can you help me to learn more?
(Another definition for startup that I've seen is " new business".)