Set loose without testing, right away (6)
I believe the answer is:
untied
'set loose' is the definition.
'without testing right away' is the wordplay.
'without testing' becomes 'untried'.
'right' becomes 'r' (common abbreviation).
'away' suggests deleting specific letters.
'untried' with 'r' removed is 'UNTIED'.
(Other definitions for untied that I've seen before include "Disconnected" , "Unfastened, knot say" , "Picked loose" , "Not fastened" , "Released from 19" .)