diagram

American  

[dahy-uh-gram] / ˈdaɪ əˌgræm /

noun

1. a figure, usually consisting of a line drawing, made to accompany and illustrate a geometrical theorem, mathematical demonstration, etc.

2. a drawing or plan that outlines and explains the parts, operation, etc., of something.

   a diagram of an engine.

3. a chart, plan, or scheme.

---

verb (used with object)

diagramed, diagrammed, diagraming, diagramming

1. to represent by a diagram; make a diagram of.

diagram British  

/ ˌdaɪəɡrəˈmætɪk, ˈdaɪəˌɡræm /

noun

1. a sketch, outline, or plan demonstrating the form or workings of something

2. maths a pictorial representation of a quantity or of a relationship

   a Venn diagram

---

verb

1. to show in or as if in a diagram

Other Word Forms

• diagrammable
  adjective
• diagrammatic
  adjective
• diagrammatically
  adverb
• misdiagrammed
  adjective
• undiagramed
  adjective
• undiagrammed
  adjective

Etymology

Origin of diagram

1610–20; < Latin diagramma < Greek: that which is marked out by lines. See dia-, -gram ¹

Explanation

A diagram is a drawing that shows the different parts of something and how they work together. If you follow a diagram for assembling bunk beds and finish with parts left over, you should ask for the top bunk, not the bottom one. Diagram goes back to the Greek verb diagraphein, meaning "to mark out by lines," and a diagram uses line drawings to explain something. Electronic equipment comes with a long instruction booklet and a one-page diagram, and it's usually the diagram that helps most in connecting the device. A diagram can also be a complex drawing, like an engineering plan for airplanes. When you make a line drawing of your own, you can use diagram as a verb, as when you diagram a sentence.

Example Sentences

This diagram serves as a visual guide to different stable quantum phases, each defined by fixed topological properties.

From Science Daily • May 4, 2026

If you think of the decisions of political leaders like a Venn diagram, often those circles don't do a lot of overlapping.

From BBC • Mar. 16, 2026

I probably don’t need to draw you a diagram.

From MarketWatch • Jan. 5, 2026

On Dec. 1, the new chancellor of the Texas Tech University system sent professors a diagram laying out a chain of approval for course material.

From The Wall Street Journal • Dec. 9, 2025

Virtually every major magazine and newspaper in the country ran a story about Fischer, often with pictures of him and a diagram of his final position against Petrosian.

From "Endgame" by Frank Brady