Flanks vs Sides

When to use each in English, with meaning, register, and examples.

Flanks

Beyond 10,000 (less common)

Sides

Top 1,000 (very common)

Most common: Sides

	Flanks	Sides
Pronunciation	🇬🇧 //flæŋks// 🇺🇸 //flæŋks//	🇬🇧 //saɪdz// 🇺🇸 //saɪdz//
Meaning	The sides of something, especially in military or body context.	The edges or surfaces of something.
Example	The soldiers advanced on the enemy's flanks.	The box has four sides that can be opened.
Register	Neutral	Neutral
How common	Beyond 10,000 (less common)	Top 1,000 (very common)
Collocations	attack the flanks, defend the flanks, flank movements, flank steak, muscles of the flanks	both sides, the side, side by side, on all sides, different sides
Antonyms	rear, center, front	center, middle
Common mistakes	Confused with 'flank' used as a verb, meaning to be at the side of., Misunderstanding which part of the body constitutes the flanks., Using 'flanks' in singular form incorrectly.	Confusing 'sides' with 'sight' when talking about vision., Using 'sides' in singular form when referring to multiple aspects.
Usage notes	Used mainly in military contexts, but also refers to the side area of the body. In sports, it can mean the sides of a playing area.	Use 'sides' when referring to the different surfaces or aspects of an object or issue. It's neutral and works in both formal and informal contexts.

See it in real clips

Avengers › Avengers Infinity War

Focus that fire on the left flank, Sam.

Flanks

"The path of the righteous man is beset on all sides...

Succession › S1 E1

- Change sides! - Hey, man.

Your eyeglasses made those two deep impressions on the sides of your nose.

"The path of the righteous man is beset on all sides...

Succession › S1 E1

- Change sides! - Hey, man.

Sides

Frequently asked questions: Flanks vs Sides

What's the difference between Flanks and Sides?

Flanks: The sides of something, especially in military or body context. Sides: The edges or surfaces of something.

Which is more common: Flanks and Sides?

Sides is the most common in everyday English.

Can you show an example of each?

Flanks: The soldiers advanced on the enemy's flanks. Sides: The box has four sides that can be opened.

Can I use Flanks and Sides interchangeably?

Not always. Flanks and Sides are related and overlap in some contexts, but they differ in register, how common they are, and usage, so swapping one for another can change the meaning or tone. Check the differences above before substituting.