Bottle in container vessel (5)
I believe the answer is:
nerve
'bottle' is the definition.
(I've seen this before)
'in container vessel' is the wordplay.
'in' indicates the answer is hidden within the clue.
'NERVE' is hidden within 'container vessel'.
(Other definitions for nerve that I've seen before include "Sensory organ; bottle" , "Cord that carries instructions from brain to body" , "Grit" , "Impudence; sensory fibre" , "Brass - steel" .)