Dined with lesbian perhaps outside entrance (7)
I believe the answer is:
gateway
'entrance' is the definition.
(I know that gateway is a type of entrance)
'dined with lesbian perhaps outside' is the wordplay.
'dined' becomes 'ate' (I've seen this in another clue).
'with' becomes 'w' (abbreviation).
'lesbian perhaps' becomes 'gay' (lesbian is a kind of gay).
'outside' means one lot of letters goes inside another.
'ate'+'w'='atew'
'atew' inserted within 'gay' is 'GATEWAY'.
(Other definitions for gateway that I've seen before include "Port" , "access to computer network" , "Connection between computer networks" , "Means of entry" , "Means of access" .)