flat iron

noun

1

: a device used for straightening hair by pressing and pulling sections between two heated metal or ceramic, flat, rectangular plates

2

usually flatiron

ˈflat-ˌī(-ə)rn 

old-fashioned : iron sense 2a

Examples of flat iron in a Sentence

Recent Examples on the Web

Now with its new flat iron, the styling suite is complete for safely silkening textured strands. — Brianna J. Heath, Vogue, 14 Aug. 2026

For Ellis Ross and her team, the flat iron needed the right products to accompany it. — Jackie Fields, PEOPLE, 14 Aug. 2026

To style, blow-dry your hair straight, curl with a curling iron or flat iron, and finish with texturizing spray. — Omenaa Boakye, InStyle, 13 Aug. 2026

Its shoulder section yields flat iron and ranch steaks, while its blade section contains the teres major, or petite tender—the third most tender muscle on the animal. — Bridget Shirvell, Martha Stewart, 18 July 2026

Word History

First Known Use

1743, in the meaning defined at sense 2

Rhymes for flat iron

• flatiron
• gridiron

Kids Definition

flatiron

noun

flat·​iron -ˌī(-ə)rn 

: iron entry 1 sense 2c