The most common and most likely answer to this crossword clue is the 9 letter word INVERTERS
I
N
V
E
R
T
E
R
S
Buddy explains!
The straight part
We know that "They might turn round" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case they might turn round = inverters.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 INVERTERS mean?
INVERTERS noun- Something that inverts, or causes inversion
- A power inverter