Google's house servant (4,4)
I believe the answer is:
home page
'google's' is the definition.
(common home page)
'house servant' is the wordplay.
'house' becomes 'home' (homing is a kind of housing).
'servant' becomes 'page' (I've seen this before**).
'home'+'page'='HOME PAGE'
(Other definitions for home page that I've seen before include "introduction to website?" , "First part of site" , "introduction to site" , "Introductory part to a website" , "website feature" .)