I know of no way to remove words that are already in the dictionary. Only words you may have added yourself. You can, however, turn off predictive text, which then will give you no words and you must type everything out yourself.
How to turn on/off Predictive Text/Text Suggestions.
Depending on your device, and android version, there are a few different ways to turn this option on/off.
Option 1.
1. Go to "Settings" and then tap "Language & Input".
2. Next tap "Default" (keyboard) and then tap your default keyboard.
3. Now tap "Configure Input Methods" and then tap "Settings" next to the keyboard you are wanting to alter.
4. Here tap "Text Input Settings", then tap "Word Suggestions".
5. On this next screen tap the option you wish...