Google recognizes HTML definition structures and some of the web’s most prominent definition sites such as wikipedia.org, wordnet.princeton.edu and so on, and it has collected adequate stock of definitions in its database.
You can navigate to your favorite online definition resource or you can just search on Google for any words or phrases’ definition:
define:RAM
Google then pumps out over 10 results trying to explain RAM to you by additionally giving the alternative URL where this term is further defined. Or:
what is RAM
Would also get you all the definition results for RAM.