(trigonometry) Any function of an angle expressible as the ratio of two of the sides of a right triangle that has that angle (e.g., sine), or that subtracts 1 from such a ratio or subtracts such a ratio from 1 (e.g., coversed sine).

(firearms) A finger-operated lever used to fire a gun. / A similar device used to activate any mechanism. / An event that initiates others, or incites a response.

(transitive) To fire a weapon. / (transitive) To initiate something. / (transitive, figuratively) To spark a response, especially a negative emotional response, in (someone).

Living in or involving trigamy. / (botany) Having three kinds of flowers — male, female, and hermaphrodite — in the same flower head.

A person who has three spouses; someone who commits trigamy / A person who has a third marriage

(mathematics) of, relating to, or constructed using trigonometry

(mathematics) A function that is the inverse of an appropriate restriction of a trigonometric function.

(mathematics) The logarithm of a trigonometric function

(mathematics) Either of a pair of trigonometric functions that have equal values when their arguments are complementary angles, e.g. sine and cosine.

A trigger that will set off a firearm when even a very small pressure is applied.