grey area

aspect, topic, etc that does not fit into a particular category, and is therefore difficult to deal with 灰色区域（不易归类故难以处理的方面、 题目等）: When the rules for police procedure were laid down, a lot of grey areas remained. 警方的程序规章定立後, 遗留下许多难以处理的灰色区域.

Greenwich, Greenwich Mean Time, greenwood, greet, greeting, greetings, gregarious, gregariously, gregariousness, Gregorian, Gregorian calendar, Gregorian chant, gremlin, grenade, grenadier, Grenoble, grep, grew, grey, grey (also esp US gray), grey matter, grey-headed, greybeard, greyhound, greyish, greyish (also esp US grayish), grid, griddle, gridiron, grief, grief-stricken, grievance, grievances, grieve, grieve over, grievous, grievous bodily harm, grievously, griffin, grill,