backside

noun

back·​side ˈbak-ˌsīd 

1

informal

a

: the part of the body that a person sits on : buttocks

I slid down on my backside, heaving or rowing myself with my arms and using my good leg for steering …

—Oliver Sacks

b

: the part of the body of a four-legged animal corresponding to the buttocks : rump sense 1a

… admits she hit the dog's backside but denies hitting it on the head.

—Ann Krueger

2

or back side : the side or surface opposite the front or face of something : the farthest or reverse side : back

A tight, rocky couloir drops down the backside of the peak …

—Mike Beaudry

The guy with the clipboard pulled me over, pointed to an innocuous little knob on the back side of the engine and said it's part of the computer and needs to be replaced.

—Tom and Ray Magliozzi

3

or back side

a

: the side opposite the homestretch on a racecourse : backstretch

When challenged on the backside the final time around, Tudor Palm would have no part of it, and burst to the lead again.

—Jackie Burke

b

: the part of a playing field or court (as in football or basketball) that is away from where the main action or play is occurring

—often used before another noun

a backside tackle

c

: the final 9 holes of an 18-hole golf course

The duo had a little trouble on the backside, though, as they bogeyed the par-3 11th hole.

—Brian Girasoli

Synonyms

• cheeks
• tail
• seat
• bum
• rump
• rear
• bottom

Examples of backside in a Sentence

our backsides were sore after sitting on those hard benches for so long

Recent Examples on the Web

Mike Green continues to impress In one two-play sequence on Tuesday, Ravens rookie outside linebacker Mike Green chased down a running play on the backside and then beat rookie tackle Carson Vinson inside to put pressure on quarterback Cooper Rush. —Jeff Zrebiec, New York Times, 30 July 2025

But the Theon 964 is the closest thing to having your hands, feet and backside directly in contact with the road. —Iain MacAuley, Forbes.com, 29 July 2025

Thompson took to Instagram with a photo dump of a recent trip to the Bahamas, and one picture appears to show Megan Thee Stallion’s backside as Klay shares a kiss with the Houston Hottie. —Michael Saponara, Billboard, 14 July 2025

As a bonus, the reversible design can also be flipped over, and the backside of the rug features the same pattern in opposite colors. —Caley Sturgill, Southern Living, 5 July 2025

Word History

First Known Use

14th century, in the meaning defined at sense 2

Rhymes for backside

• abide
• allied
• applied
• aside
• astride
• azide
• bankside
• bastide
• bayside
• bedside
• belied
• beside

Kids Definition

backside

noun

back·​side ˈbak-ˈsīd 

informal

: buttock sense 2a

Medical Definition

backside

noun

back·​side -ˌsīd 

: buttocks

—often used in plural