Game like bingo (5)
I believe the answer is:
'game like bingo' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for lotto that I've seen before include "Bingo - Venetian painter" , "Bingo-like game" , "Housey-housey, bingo" , "Children's game; lottery" , "Prize draw" .)