Regulars in shore leave getting blotto in port (2,5)
I believe the answer is:
le havre
'port' is the definition.
(I've seen this before)
'regulars in shore leave getting blotto' is the wordplay.
'regulars in' means one should take alternating letters.
'getting blotto' indicates anagramming the letters.
The alternate letters of 'shore' are 'hr'.
'hr'+'leave'='hrleave'
'hrleave' anagrammed gives 'LE HAVRE'.
'in' is the link.
(Other definitions for le havre that I've seen before include "French Channel port" , "Port in Normandy" , "Port city of northern France" , "Northern French port" .)