The most common and most likely answer to this crossword clue is the 3 plus 5 letter word GAS METER
I've seen this crossword clue in The Daily Telegraph
G
A
S
M
E
T
E
R
More clues leading to the result GAS METER
- Reg’s team rearranged home fixture
- Waffle clock? This accounts for its consumption
- Fuel holder, nothing left but a measuring device
- Fuel tank lacks ordinary means of tapping it
- Gambler bringing up son that keeps track of consumption
- Losing heart, the gamers destroyed what’s under the stairs?
- Foolish East German ignoring an indicator of fuel use
Buddy explains!
The straight part
We know that "what’s under the stairs?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case what’s under the stairs? = gas meter.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.