verb
fortify
FOR-tuh-fy/ˈfɔːrtɪfaɪ/
To build up strength against a threat or weakness.
Workers fortify the timber gate with iron braces and extra beams.

Etymology
Literally “make strong,” fortify applies both to providing walls and defenses and to strengthening someone mentally or morally against difficulty.
In context
further reinforcements from the imperial navy and astra militarum were deployed from orbit to fortify the cathedral
More examples
- Her coach's encouragement fortifies her resolve before the race.
- A hearty breakfast fortifies us for the long hike.
- Manufacturers fortify cereal with vitamins and minerals.
Forms
fortify · fortifies · fortified · fortifying
fortification noun — The act of making something stronger.
Similar words
- strengthen
- Broader term for making anything stronger, not necessarily against threats.
- reinforce
- Emphasizes adding support to something already in place.
- bolster
- Often means supporting confidence, resolve, or a weak position.