tangent

Từ điển Oxford Advanced Learner 8th

tan·gent [tangent tangents] BrE [ˈtændʒənt] NAmE [ˈtændʒənt] noun
1. (geometry)a straight line that touches the outside of a curve but does not cross it
2. (abbr.tan) (mathematics)the ↑ratio of the length of the side opposite an angle in a ↑right-angled triangle to the length of the side next to it
compare ↑cosine, ↑sine
Idiom: ↑go off at a tangent
See also: ↑go off on a tangent

Word Origin:
late 16th cent. (in sense 2 and as an adjective): from Latin tangent- ‘touching’, from the verb tangere.

Example Bank:
•Laura's mind went off at a tangent.
•The cart track branches off at a tangent.