Google-search – How to show Google’s word definition

*EDIT: And looking further, it seems someone else has identified other sources so maybe my hypothesis doesn't hold. That article gives much better insight than I do. (The page is also 4 years old, but the most relevant post I could find.)

Doing a few random searches, it looks like all the answers come from the same sets of sources. My educated guess would be that Google has already determined sources which are trustworthy/reliable and have written algorithms to parse/search these resources and return these results in an order which is consistent with its other search algorithms.

I base this hypothesis on that I haven't seen any sources outside of these specific ones in approx 10 different searches:

• en.wikipedia.org/wiki/
• wordnetweb.princeton.edu/
• en.wiktionary.org/

This page offers some addditional suggestions on how to properly identify definitions in your HTML however the no conclusion was reach on how Google sources these definitions.

Put + directly in front of the word or phrase. I use this all the time. For example

+"MAPB agarose" 

Note: This is no longer true.

The + operator has been replaced.
To search for an exact word or phrase, use double quotation marks: hacker "news"

So you just need the quotes now.