to add defensive fortifications to a site to withstand attack — as in "fortify the camp"
to make a structure or organization stronger — as in "fortify the wall"
to inspire emotional and mental strength — as in "fortify her spirits"
to strengthen an argument — as in "fortify our argument"
to add nutrients to increase the healthfulness — as in "bread fortified with folic acid and iron"
to add alcohol to make a drink stronger and/or less prone to spoiling — as in "port, sherry, madeira, and other fortified wines"
Fortified by the former (and never in the company of the latter), our senior class then rode the subway back to Boston, where— once again, falsifying our age—we gained admission to the striptease performances that were much admired by our age group at an establishment known as Old Freddy's.
There are no more uses of "fortify" in A Prayer for Owen Meany.