Yes, there is: http://www.usingenglish.com/glossary.html
Hi, I've joined this site to improve my knowledge of English,which has waned somewhat since my schooldays 40years ago. I've been doing the "parts of speech" tests which talk about adverbs, pronouns, definite articles etc. Although I have heard of these I cannot remember what they are. Is there somewhere on the site that explains them all.