(differential geometry) A straight line touching a curve at a single point without crossing it there.

(mathematics) A function of an angle that gives the ratio of the sine to the cosine, in either the real or complex numbers. Symbols: tan, tg.

A topic nearly unrelated to the main topic, but having a point in common with it.

(art) A visual interaction between two or more lines or edges that creates a perceived relationship between them, often in a way that the artist did not intend.

(music) A small metal blade in a clavichord that strikes the strings to produce sound.

(geometry) Touching a curve at a single point but not crossing it at that point.

Of a topic, only loosely related to a main topic.

(rail transport, of track) Straight; not horizontally curved.