a grey area — an unclear or undefined situation
a situation, rule, or topic that is not clearly defined and where it is difficult to say what is right or wrong, or what should be done.
Say it like a native
Textbook The legality of this practice remains ambiguous and ill-defined.
Native It's a bit of a grey area.
'Grey area' is the everyday way to flag 'unclear/undefined'; the paraphrase is legalese.
Pattern: a grey area (in/between/around something)
In use
- The law on using drones is still a grey area, so people aren’t always sure what’s allowed.society
- There are many grey areas when it comes to privacy online, as technology is changing faster than the laws can keep up.IELTS speaking
Common mistake
✗ It's a grey zone legally.
✓ It's a grey area legally.
The fixed phrase is 'grey area' (BrE) / 'gray area' (AmE), not 'grey zone'.
Common collocations
a grey area— a bit of, legal, falls into, ethical
Don't confuse it
This sense is not about something literally coloured grey, but about a situation that is not clear-cut. It differs from simply saying something is 'complicated' or 'difficult'; a grey area specifically means there is uncertainty about what is correct or allowed.