# tangent

/ˈtændʒənt/ (US) · /tˈændʒənt/ (UK)

Source: https://englishreference.com/word/tangent
Updated: 2026-08-27

## Senses

### 1. conversation/topic

noun · CEFR B2 · Informal

a sudden change to a different subject that is only slightly related to what you were talking about.

For teachers: a sudden divergence from a main line of thought or course of action into a marginally related topic.

- The professor went off on a long tangent about his cat during the history lecture.
- The meeting was productive until the CEO went off on a tangent regarding his recent holiday, which delayed the final vote by twenty minutes.

Usage: Commonly used in the phrase 'go off on a tangent'.

### 2. geometry

noun · CEFR C1 · Technical

a straight line that touches a curve at one point but does not cross it.

For teachers: a straight line or plane that touches a curve or curved surface at a point, but if extended does not cross it at that point.

- The teacher asked us to draw a tangent to the circle at point P.
- The student calculated the slope of the tangent to the curve at the specific point where the derivative was zero.

### 3. trigonometry

noun · CEFR C1 · Technical

a mathematical function used to calculate the relationship between the sides of a triangle.

For teachers: a trigonometric function that represents the ratio of the opposite side to the adjacent side of a right-angled triangle.

- You can find the height of the tree if you know the angle and the tangent.
- In the final exam, students were required to solve for the unknown angle using the inverse tangent function.

### 4. art/composition

noun · CEFR C2 · Technical

a mistake in a drawing where two lines touch in a way that looks confusing or flat.

For teachers: an unintended visual relationship created when two edges or lines touch, often resulting in a loss of depth or clarity in the composition.

- The artist moved the tree in the painting to avoid a tangent with the character's head.
- The illustrator carefully adjusted the character's silhouette to eliminate a distracting tangent where the sword edge met the background mountain range.

### 5. music/clavichord

noun · CEFR C2 · Technical

a small metal part in an old keyboard instrument that hits the strings to make sound.

For teachers: a small brass blade in a clavichord that strikes the string to produce sound and remains in contact with it to determine the pitch.

- The musician adjusted the tangent to make sure the note sounded clear.
- Unlike a piano hammer, the clavichord tangent stays against the string, allowing the player to influence the sound through pressure.

### 6. touching a curve

adjective · CEFR C1 · Technical

describing a line that touches a curve at one point.

For teachers: meeting a curve or surface at a point and having at that point the same direction as the curve or surface.

- The tangent line just barely touches the edge of the circle.
- The physicist explained that the velocity vector is always tangent to the path of the moving particle.

## Examples

- He went off on a tangent about his cat during the meeting.
- The professor started with a lecture on physics but went on a long tangent about his summer vacation.
- While the initial argument was sound, the author frequently veered off on a tangent regarding historical anecdotes that did little to support the primary thesis.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.