Add a custom word to Google Japanese keyboard I am wanting to type a word in Japanese that has a unique reading (not the standard onyomi or kunyomi). As such, I'd like to add it to the Google Japanese keyboard so that I can simply type the kana, and the desired kanji will show up. At the moment I have to type out each individual kanji by their standard readings to write the desired word.

How can I add a custom reading to the Google Japanese keyboard?

For clarification, please see Tip #9 on this page for an example of how to do this in Windows:
http://nihonshock.com/2010/04/12-japanese-ime-tips/
Gboard (Google Keyboard) has a very simple way to add new words to it.

Open the Gboard app, go to 'dictionary' > 'personal dictionary' > [Japanese] > plus (+) symbol on the top right. Now, type the desired word, and add a shortcut, that way every time you type the shortcut, it will give you the option to switch to the desired word.

For example, if I want to type the word 
Привет in Russian, but I don't want to switch my keyboard from English to Russian just to type that word, so I made a shortcut that every time I write the letter P the word will show up in the suggestion bar. See screenshot below