How would I make a cell that contains a keyword display information that defines that keyword from another sheet when hovered over with the mouse?

Question

In Google Sheets I would like to have a definition of a keyword display when you hover the mouse over the usages of that word in other sheets shared by the file. My goal is to have the info that is referenced to be available at a glance without adding even more text to an individual cell

The file has lists of items in a row with their traits and information listed. I have a column where there are Keywords that are defined on another sheet in the file.

So if I had a cell with two keywords in it that were defined on another sheet such as.

Sheet 1, Cell A1:    Keyword.A and Keyword.B

Sheet 2, Cell A1: Keyword.A
Sheet 2, Cell A2: Keyword.A's Definition

Sheet 2, Cell B1: Keyword.B
Sheet 2, Cell B2: Keyword.B's Definition

How would I be able to display the text from Sheet 2, Cells A1-B2 while the mouse is hovering over Sheet 1, Cell A1?

I prefer that the keyword would both display the definition from another sheet as well as act as a direct link to the definition in the other sheet. However the information displayed on mouse over is the more important of the two.

So far I have attempted to add a note to the cell with the keyword. However I have not figured out how to make that note display the information from another cell without manually copy and pasting the definition.

Ultimately my question is. How would I have a definition of a keyword display while I am hovering over it? As well as have that keyword act as a link to the same definition that is being displayed?
Also if this is an option, would it also be a possibility to have all instances of that keyword automatically update in the file to display that info?

My goal is to make an easy to reference Google sheet of all the weapons and armors for my starfinder group to have for quick reference on game nights. There are very good online options available for us to use such as. Archives of Nethys, StarjammerSRD and Dragonlash. These sites all use hyperlinks for the item properties that take you to a second page and I was hoping to make referencing the rule even faster to make it easier for us. I of course do not own the rights to the game and will not be distributing the project it is solely an easy of access project for a group of people new to a game that we enjoy.

The image below is an example of the tables we are referencing with the far right column being the primary area where I would like to have Keyword references available on mouseover.

Answer 1

From the question

In google sheets I would like to have a definition of a keyword display when you hover the mouse over the usages of that word in other sheets shared by the file.

You might use a note to the cell with the keyword definition. It could be added manually, or automatically by using Google Apps Script or the Google Sheets API.

Another option is to add a comment to the cell. This could be added manually (at this time I'm no sure that comments could be added programmatically to a cell)

One more option might be add to each keyword a hyperlink to a webpage having a title (in the HTML sense) and / or thumbnail showing the keyword definition.

If you are open to another approach you might use Google Apps Script to add a custom sidebar to display the keyword(s) definition. In order to make this work to have to use client-side JavaScript to continuously pool the active cell.