The term 'which' can be used in a variety of ways, depending on the context. The two most common crossword solutions for this term are 'who' and 'THAT'. 'Who' is a pronoun used to refer to a person or people previously mentioned or implied, while 'THAT' is a pronoun used to refer to a thing or things previously mentioned or implied. Both pronouns are used to ask questions or make statements about the identity of something.