Main performer abandoning vessel in sudden movement (5)
I believe the answer is:
start
'sudden movement' is the definition.
(I've seen this in another clue)
'main performer abandoning vessel in' is the wordplay.
'main performer' becomes 'star' (eg the star of a show).
'abandoning' is a deletion indicator.
'vessel' becomes 'tin' (type of container).
'tin' with 'in' taken away is 't'.
'star'+'t'='START'
(Other definitions for start that I've seen before include "Begin with sudden movement of surprise" , "Set in motion" , "Jerk" , "Begin; flinch" , "lead" .)