The most common and most likely answer to this crossword clue is the 5 letter word KAYOS
I've seen this crossword clue in The Guardian
K
A
Y
O
S
Buddy explains!
The straight part
We know that "floors" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case floors = kayos.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.
What does KAYOS mean?
KAYOS noun- A knockout (in boxing).