Refuse to install fonts in MS Word Docs When opening one of my documents in Word 2015 (15.17.1) on MacOS 10.13.2, I'm asked to download a series of fonts including: STHeiti and Osaka.

I know I could have these fonts installed to make word happy. How to do this was explained in another SO question. 

I have a very small HD however, so I DON'T want to install these fonts. How can I tell word to stop prompting me to do it please?

Side remark: I am also surprised by the massive amount of space installing these not so well known fonts requires.
There is no way of bypassing the system. If you have a second hard drive, you can back up data to the second drive (to save disk space), install the fonts, enable them and then DELETE them (in font book), and then restore your files from the external drive.

Not very convenient, but works.