Refurbished marina with empty room closely joined (3,2,3)
I believe the answer is:
arm in arm
'closely joined' is the definition.
(eg walking arm in arm)
'refurbished marina with empty room' is the wordplay.
'refurbished' is an anagram indicator.
'with' means one lot of letters goes inside another.
'empty' means to remove the middle letters.
'room' with its middle taken out is 'rm'.
'marina' with letters rearranged gives 'ainarm'.
'ainarm' enclosing 'rm' is 'ARM-IN-ARM'.
(Other definitions for arm in arm that I've seen before include "Closely linked" , "having intimate contact" , "Linked at the elbows" , "Linked together" , "showing solidarity" .)