flank

American  

[flangk] / flæŋk /

noun

• flanks
  plural

1. the side of an animal or a person between the ribs and hip.

2. the thin piece of flesh constituting this part.

3. a slice of meat from the flank of an animal.

4. the side of anything, as of a building.

5. Military, Navy. the extreme right or left side of an army or fleet, or a subdivision of an army or fleet.

6. Fortification.

   1. the right or left side of a work or fortification.

   2. the part of a bastion that extends from the curtain to the face and protects the curtain and the opposite face.

7. Machinery. (on a screw thread or the like) either of the two vertical inclined surfaces between the crest and the root.

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verb (used with object)

• flanks,
  present (3rd person singular)
• flanked,
  past participle,  past
• flanking
  present participle

1. to stand or be placed or posted at the flank or side of.

   Synonyms:

   border, skirt, edge, line

2. to defend or guard at the flank.

3. Military. to menace or attack the flank of.

4. to pass around or turn the flank of.

verb (used without object)

• flanks,
  present (3rd person singular)
• flanked,
  past participle,  past
• flanking
  present participle

1. to occupy a position at the flank or side.

2. to present the flank or side.

flank British  

/ flæŋk /

noun

1. the side of a man or animal between the ribs and the hip

2. (loosely) the outer part of the human thigh

3. a cut of beef from the flank

4. the side of anything, such as a mountain or building

5. the side of a naval or military formation

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verb

1. to be located at the side of (an object, building, etc)

2. military to position or guard on or beside the flank of (a formation, etc)

3. military to move past or go round (a flank)

Usage

What is a basic definition of flank? A flank is space between the lowest rib and hip of an animal or person. To flank something means to stand at the side of something. In the military, a flank is a left or right side of an army or fleet of ships. Flank has several other senses as a noun and a verb. The space on your torso between your lowest rib and your hip is called your flank. Animals like cows and horses also have sides referred to as flanks. If a slice of meat comes from this part of an animal’s body, it is a flank cut or flank steak.

• Used in a sentence: The tree branch poked me in my left flank. 

More generally, a flank is the side of anything.

• Used in a sentence: The ball bounced off the left flank of the house. 

In this sense, flank is used to mean to stand or be located at the side of something. A person or thing that flanks something is called a flanker.

• Used in a sentence: Orange trees flanked both sides of the river.

Flank is used in a military sense to refer to the sides of an army. For example, if an army was lined up in rows of soldiers, the soldiers on either end of the rows would make up the army’s flank. An army’s flank is described with directional terms, such as left or right, or compass directions, that is, north, south, east, or west.

• Used in a sentence: The left flank collapsed under the intense arrow fire. 

Flank is used in a similar sense as a verb to mean to attack or harass an army’s flank.

• Used in a sentence: The Roman soldiers charged out of the woods and managed to flank the Greek army. 

Other Word Forms

Derived Forms

• unflank
  verb (used with object)
• well-flanked
  adjective

Inflected Forms

Nouns

• flanks
  plural

Participles

• flanking
  present
• flanked
  past

Conjugated Forms

Present

• flank
  simple
• flanks
  simple
• have flanked
  perfect
• has flanked
  perfect
• am flanking
  progressive
• are flanking
  progressive
• is flanking
  progressive
• have been flanking
  perfect progressive
• has been flanking
  perfect progressive

Past

• flanked
  simple
• had flanked
  perfect
• was flanking
  progressive
• were flanking
  progressive
• had been flanking
  perfect progressive

Future

• will flank
  simple
• will have flanked
  perfect
• will be flanking
  progressive
• will have been flanking
  perfect progressive

Etymology

Origin of flank

before 1100; Middle English; late Old English flanc < Old French < Frankish; compare Old High German hlanca loin

Explanation

A flank is the side of something, whether of beef or a military formation. Although flank is specifically used to talk about a cut of meat, or the right or left side of a military formation, we also use it in those same senses for other objects or even metaphorically. You might, for example, refer to the more conservative flank of a political party. This word can also be used as a verb. If you see someone walking down the street with bodyguards on either side, she's flanked by guards.

Example Sentences

See Examples For:

flank flanks flanked flanking

It is also a partner of Baltic and Nordic nations in protecting the northern flank of the North Atlantic Treaty Organization that runs through the Arctic.

From The Wall Street Journal ● Sep. 23, 2026

It comes after Nato forces shot down a drone over Lithuania in the latest security scare on the alliance's eastern flank, where tensions remain high amid Russia's full-scale invasion of Ukraine.

From BBC ● Sep. 15, 2026

In recent months, states across NATO's eastern flank have faced a raft of hostile actions from Moscow and Minsk ranging from drone incursions to cyberattacks.

From Barron's ● Sep. 15, 2026

Shasta summit, leaving them stranded on the mountain’s southeastern flank.

From Los Angeles Times ● Sep. 3, 2026

It bounced from the iron flank of a tank and broke into petals.

From "Milkweed" by Jerry Spinelli

The gates blocking it, and the security checkpoints along its flanks, will dramatically limit the public’s desire to enter, and change the tenor and experience of a space that should feel porous and inclusive.

From Los Angeles Times ● Oct. 1, 2026

Effectively that is Shaw as first-choice left-back, with Noussair Mazraoui as back-up, in a position he admittedly plays in for Morocco, supported by Diogo Dalot, who has switched flanks before, and Harry Amass.

From BBC ● Sep. 2, 2026

It warned of hot volcanic debris flows down Fuego's slopes, with communities on the western and southern flanks at the greatest risk.

From Barron's ● Aug. 4, 2026

The researchers found that rift flanks begin to flatten relatively quickly once tectonic movement ends.

From Science Daily ● Jul. 25, 2026

Then she saw the dogs again and they were racing after the stag, his brown flanks flashing between the trunks.

From "Ash" by Malinda Lo

Near the central village of Baziafla, flanked by tall grass, the pit was excavated over several weeks with spades, pickaxes and crushers, before the miners were driven out of town by the local authorities.

From Barron's ● Sep. 30, 2026

Kennedy is typically flanked by bodyguards in public.

From The Wall Street Journal ● Sep. 23, 2026

The blue-lit monotony of every day is replaced by warm amber table lamps and dimly lit corners flanked by books on all sides.

From Salon ● Sep. 7, 2026

They were flanked by seven security guards and other staff and two Slovak interpreters.

From BBC ● Sep. 3, 2026

Nyame, flanked by Leopard and Python, took stock of the damage to the marina.

From "Tristan Strong Punches a Hole in the Sky" by Kwame Mbalia

Kinjo says that reefs flanking his seaside farm consist entirely of corals he cultivated, with their natural peers "no longer able to keep up with a tremendous increase in stress" in the anthropogenically polluted ocean.

From Barron's ● Jul. 29, 2026

Primitive by U.S. standards, the silos are little more than deep holes dug into the side of a mountain that point toward the nearby Persian Gulf, flanking a paved entrance to the underground facility.

From The Wall Street Journal ● Mar. 5, 2026

That emotional depth lifts each scene, even the darkest— just as the supergroup of talent flanking Smart and Einbinder does.

From Salon ● Apr. 10, 2025

Behind him, flanking a rolltop desk, were framed pictures of two sets of brothers: John F. and Robert F. Kennedy, and Schiff and his elder sibling, Dan.

From Los Angeles Times ● Nov. 10, 2024

The ghosts in the garden glided into position, flanking Lazlo from behind.

From "Strange the Dreamer" by Laini Taylor