triangular

adjective

tri·​an·​gu·​lar trī-ˈaŋ-gyə-lər 

1

a

: of, relating to, or having the form of a triangle

a triangular plot of land

b

: having a triangular base or principal surface

a triangular table

a triangular pyramid

2

a(1)

: of, relating to, or involving three elements

a triangular agreement

(2)

of a military group : based primarily on three units

b

: of or relating to a love triangle

triangularity

(ˌ)trī-ˌaŋ-gyə-ˈler-ə-tē 

-ˈla-rə-tē

noun

triangularly

trī-ˈaŋ-gyə-lər-lē 

adverb

Examples of triangular in a Sentence

Recent Examples on the Web

The dough is formed into a disk and baked, then when cooled for 15 minutes, cut into triangular wedges. —Cathy Thomas, Oc Register, 1 Dec. 2025

Experts told state broadcaster China Media Group that the YJ-17 acts as a boost-glide vehicle with a flat, triangular front end, similar to the DF-17 ballistic missile. —Kapil Kajal, Interesting Engineering, 28 Nov. 2025

Their adhesive backing keeps them in place through heat and movement, and the brand also offers a triangular sticky style meant for plunging V-necklines. —Malia Griggs, Glamour, 27 Nov. 2025

Last year’s Babygirl and the upcoming Marty Supreme also have triangular elements. —Brian Davids, HollywoodReporter, 25 Nov. 2025

Word History

Etymology

Middle English trianguler, from Late Latin triangularis, from Latin triangulum

First Known Use

14th century, in the meaning defined at sense 1a

Phrases Containing triangular

• triangular number

Rhymes for triangular

• quadrangular
• rectangular
• subangular
• angular
• subtriangular

Kids Definition

triangular

adjective

tri·​an·​gu·​lar trī-ˈaŋ-gyə-lər 

1

: of, relating to, or having the form of a triangle

2

: having a triangular base or principal surface

a triangular pyramid

Medical Definition

triangular

noun

tri·​an·​gu·​lar trī-ˈaŋ-gyə-lər 

: triquetral bone