Google rival with old house (5)
I believe the answer is:
bingo
'house' is the definition.
(both are used to announce you have won in bingo)
'google rival with old' is the wordplay.
'google rival' becomes 'bing' (I've seen this in another clue).
'with' is a charade indicator (letters next to each other).
'old' becomes 'o' (abbreviation as in OT - Old Testament).
'bing'+'o'='BINGO'
(Other definitions for bingo that I've seen before include "House!" , "Game of chance" , "Game in which "two little ducks" might be called" , "Number-calling game" , "Popular gambling game in which numbers are called at random" .)