fortify

verb

for·​ti·​fy ˈfȯr-tə-ˌfī 

fortified; fortifying

transitive verb

: to make strong: such as

a

: to strengthen and secure (a place, such as a town) by forts or batteries

a city fortified by high walls

b

: to give physical strength, courage, or endurance to

fortified by a hearty meal

c

: to add mental or moral strength to : encourage

fortified by prayer

fortified by early successes

d

: to strengthen or enhance by the addition of some substance or ingredient: such as

(1)

: to add distilled grape spirits to (wine) during fermentation to increase the alcohol content

… both the red and white versions we get in this country have been American-made-from California wine fortified with a touch of brandy.

—Jim Nelson

(2)

: to enrich (food) by adding ingredients (such as vitamins or minerals) to improve the nutritional value

… make sure any soy milk you buy is fortified with vitamin D, an essential nutrient for bone health.

—Selene Yeager

intransitive verb

: to erect fortifications

fortifier

ˈfȯr-tə-ˌfī(-ə)r 

noun

Did you know?

Medieval cities were fortified against attack by high walls, and volunteers may fortify a levee against an overflowing river by means of sandbags. Foods can be fortified by adding vitamins, but "fortified wines", such as sherry and port, have brandy (a "stronger" drink) rather than vitamins added to them. By adopting good exercise habits, you can fortify your body against illness. And fortifying needn't always be physical. An author's reputation may be fortified by the success of his new book, or a prosecutor can fortify a case against a suspect by finding more evidence.

Synonyms of fortify

• brace
• strengthen
• ready

Examples of fortify in a Sentence

fortify a city against attack

a city fortified by high walls

Support for his theories has been fortified by the results of these experiments.

He took a deep breath to fortify himself before stepping onto the stage.

milk fortified with vitamin D

Recent Examples on the Web

The Olive and June product can also be applied daily to bare nails as an intensive strengthening treatment that not only fortifies your claws, but also repairs ridges, discoloration, and pesky peeling along the way. —Kyra Surgent, InStyle, 21 Jan. 2026

Canada’s defense commitment Canada has spent nearly a billion dollars fortifying its southern border. —Paula Newton, CNN Money, 20 Jan. 2026

The sparkling Sun turns on the lights in your 4th House of Nesting, inviting you to fortify your base with practical moves. —Tarot.com, Hartford Courant, 19 Jan. 2026

The project seeks to fortify major infrastructure to spur an economic renaissance based on boosting jobs in the artificial intelligence, semiconductor manufacturing, and energy sectors. —Emily Hallas, The Washington Examiner, 17 Jan. 2026

Word History

Etymology

Middle English fortifien, from Anglo-French fortifier, from Late Latin fortificare, from Latin fortis strong

First Known Use

15th century, in the meaning defined at transitive sense

Rhymes for fortify

• abscissae
• alibi
• alkali
• alumni
• amoebae
• amplify
• annuli
• beautify
• brachii
• butterfly
• calculi
• certify

Kids Definition

fortify

verb

for·​ti·​fy ˈfȯrt-ə-ˌfī 

fortified; fortifying

: to make strong: as

a

: to strengthen by military defenses

fortify a town

b

: to give strength or endurance to

fortify the body against illness

a team fortified by the cheering crowd

c

: to add material to for strengthening or improving : enrich

fortify a soil with fertilizer

milk fortified with vitamin D

fortifier

-ˌfī(-ə)r 

noun