Take possession of flash vessel (4,2)
I believe the answer is:
move in
'take possession of' is the definition.
Although both the answer and definition are verbs in their base form, I cannot understand how one could define the other.
'flash vessel' is the wordplay.
'flash' becomes 'mo' (both mean a very short period of time).
'vessel' becomes 'vein' (vein is a kind of vessel).
'mo'+'vein'='MOVE IN'
Can you help me to learn more?
(Another definition for move in that I've seen is " Take up new home".)