Toilet getting dry internally? It’s something of a gamble (5)
I believe the answer is:
lotto
'a gamble' is the definition.
(I've seen this before)
'toilet getting dry' is the wordplay.
'toilet' becomes 'loo' (loo can informally mean a toilet).
'getting' means one lot of letters goes inside another.
'dry' becomes 'tt' (abbreviation for teetotal).
'loo' enclosing 'tt' is 'LOTTO'.
'internally? it's something of' is the link.
This may not be correct. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for lotto that I've seen before include "gamble" , "Children's game similar to bingo" , "Children's game; lottery" , "Game of chance based on numbered balls being drawn at random" , "National gambling game" .)