Final answer:
Words in a thesaurus can be organized alphabetically or by index, helping users find synonyms and related terms.
Step-by-step explanation:
The two ways words may be arranged in a thesaurus are by alphabet and by index. In an alphabetical arrangement, words are listed in the same way as in a dictionary, which makes it easy to find words if you know how to spell them. On the other hand, an index in a thesaurus groups words by concept or category, helping users find synonyms and related words even when they are not starting with the specific word in mind.