Hello. I am going to purchase a thesaurus. No special purpose, just want to be able to look up synonyms for certain verbs, adjectives, etc. so I don't rely on the same words all the time while writing papers.

Merriam Webster seems to make various thesauruses: here's a regular thesaurus, a thesaurus for students, collegiate thesaurus, and a new roget's pocket thesaurus. I was confused what the difference was between these. When I looked at the description for the student thesaurus (which is cheaper), it said it was for grades 3-6! I thought, ok, this is a children's thesaurus. But when I looked at an example page of that book, I didn't even know some of those words: abeyant, abnegation, etc. I have never met a third grader who uses words like that.

Can this student thesaurus really function as a normal thesaurus? Anyway, just looking to see if anyone had used any of these that might be able to give some feedback on the differences between them. I have never owned a thesaurus before. Thanks!