Compilers game to pirouette always entrance (7)
I believe the answer is:
gateway
'entrance' is the definition.
(I know that gateway is a type of entrance)
'compilers game to pirouette always' is the wordplay.
'compilers' becomes 'we' (the crossword compiler and their colleagues).
'game' becomes 'tag' (children's playground game).
'to pirouette' says the letters should be written in reverse (I've seen 'pirouetting' mean this (pirouette is a spin in ballet - letters spin round)).
'always' becomes 'ay' (archaic term for 'always').
'we'+'tag'='wetag'
'wetag' backwards is 'gatew'.
'gatew'+'ay'='GATEWAY'
(Other definitions for gateway that I've seen before include "Port" , "Closable opening" , "access to computer network" , "Means of entry" , "Connection between computer networks" .)