From Longman Dictionary of Contemporary Englishgrey areagrey areaCLEAR/EASY TO UNDERSTANDused to talk about a situation in which something is not clearly a particular thing, so that people are not sure how to deal with it people in the grey area between loyalty and opposition to the government → grey
Examples from the Corpus
grey area• Of course there's a grey area.• There is one type of appeal which falls in the grey area between review and supervision.• It only remains to add that there is - damn it - a thin grey area between the two.• Sometimes a contractual term lies in a grey area between the two.• Human beings can't live on grey areas for ever - unless it enters their soul.• There were grey areas in what she had told him - or rather allowed him to believe.• Nowhere is it easier to blackmail than in the criminal underworld and the grey areas of conduct that surround it.• There are far too many grey areas with endless different interpretations open to every side. 