To make something stronger, more secure, or more resistant to attack; to strengthen the resolve or courage of a person.
From Latin 'fortis' (strong) + 'facere' (to make). This verb traces to French 'fortifier,' which combined Latin elements to mean 'to make strong.'
You can fortify a castle with walls, a person with courage, or cereal with vitamins—the word works because it captures any kind of strengthening, physical or psychological.
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