: what is or was the distinct and especially nameable identity of each member of a group — used as a direct or indirect question
those two fellows are the Jones brothers, John and William, but which is which
so many kings of France named Louis that I can hardly remember which was which
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used when two or more people or things are difficult to distinguish from each other
there is no confusion as to which is which
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which is which
— used to say that you are unsure about the identity of each member of a group
The two words sound alike, so it's hard to remember which is which.
One of the twins is named John and the other William, but which is which?
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Main Entry: ↑which
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ˌwhich is ˈwhich idiom
used to talk about distinguishing one person or thing from another
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The twins are so alike I can't tell which is which.
Useful english dictionary. 2012.