Counters and equipment found in laboratory (7)
I believe the answer is:
retorts
I believe this is a double definition.
'counters' is the first definition.
(I've seen this before)
'equipment found in laboratory' is the second definition.
(type of container used in chemistry)
'and' is the link.
(Other definitions for retorts that I've seen before include "Makes witty or angry reply" , "Counters" , "laboratory equipment" , "Sharp replies or rejoinders" .)