The answer's in the lab (6)
I believe the answer is:
retort
'the answer's' is the definition.
(I've seen this before)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for retort that I've seen before include "Quick answer - laboratory vessel" , "Answer in retaliation" , "Lab. vessel; quip" , "Rotter (anag.)" , "Witty/sharp reply" .)