I've learned a lot about sailing, and continue to do so, by doing a web-search for sailing terms while reading forum discussions and articles on the internet
. I simply copy the unknown term, open another tab, and paste the term into the URL box. The search engine
does the rest.
As an example, I didn't know the meaning of 'heave to.' So I searched the term, read why and how the maneuver is done, then went out and practiced it on my boat. A glossary might have given the definition of 'heave to,' but it would not have been as informative as the descriptions I read. Go ahead and look up 'heave to' in the glossary that Ex-Calif linked to; its definition is accurate, but is it informative? Then search the term 'heave to' and read a couple of the articles - you'll see the difference I'm writing about.
But you really need to get sailing to truly understand. Why wait? With a small boat you can learn lots, even on a small, inland lake.