Club accommodating old vessel (4)
I believe the answer is:
boat
'vessel' is the definition.
(I know that boat is a type of vessel)
'club accommodating old' is the wordplay.
'club' becomes 'bat' (as in sporting equipment).
'accommodating' is an insertion indicator.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'bat' going around 'o' is 'BOAT'.
(Other definitions for boat that I've seen before include "See 12 Down" , "Contest on the Thames" , "Small vessel" , "Water transport" , "Vehicle for travelling over water" .)