Word indices is a term that refers to the alphabetical listing of words in a reference work and their respective page numbers. However, there are various other synonyms for word indices. One of these synonyms is `alphabetical index`, which denotes an index where the entries are arranged in alphabetical order. Another synonym is `lexicon`, which is a dictionary or vocabulary that lists words and their meanings, often in a specific language. A third synonym for word indices is `thesaurus`, which is a reference work that lists words grouped together according to similarity of meaning. In conclusion, while word indices is a commonly used term, there are several other synonyms that can be used in its place depending on the specific context and purpose of the reference work.