trigonometry

Definitions:

The science of determining the sides and angles of triangles by means of certain parts which are given.
- Nuttall's Standard dictionary of the English language. By Nuttall, P.Austin. Published 1914. (noun) (n.) (noun)
Mathematics which treats of the relations between the sides and angles of triangles; a text treating of this science.
- The Winston Simplified Dictionary. By William Dodge Lewis, Edgar Arthur Singer. Published 1919. (noun) (n.) (noun)
Science which treats of triangles and their measurement.
- The Clarendon dictionary. By William Hand Browne, Samuel Stehman Haldeman. Published 1894. (noun) (n.) (noun)
In math., the application of number to express the properties of angles or of circular arcs, as well as to exhibit the mutual relations of the sides and angles of triangles to one another.
- Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874. (noun) (n.) (noun)
The branch of mathematics which treats of the relations between the sides and angles of triangles.
- The american dictionary of the english language. By Daniel Lyons. Published 1899. (noun) (n.) (noun)
Trigonometrically.
- The Winston Simplified Dictionary. By William Dodge Lewis, Edgar Arthur Singer. Published 1919. (adverb) (adv.) (adverb)
Trigonometric, trigonometrical.
- The Winston Simplified Dictionary. By William Dodge Lewis, Edgar Arthur Singer. Published 1919. (adjective) (adj.) (adjective)
Trigonometrical.
- The Clarendon dictionary. By William Hand Browne, Samuel Stehman Haldeman. Published 1894. (noun) (n.) (noun)

Usage examples:

The thickness may also be calculated by trigonometry
- The Elements of Geology by William Harmon Norton
They found them deficient in trigonometry and canned them off the team.
- At Good Old Siwash by George Fitch
After they had given the usual time to their studies, Hugh, setting Margaret some exercises in English to write on her slate, while he helped David with some of the elements of Trigonometry and again going over those elements with her, while David worked out a calculation- after these were over, and while Janet was putting the supper on the table, Hugh pulled out his volume, and, without any preface, read them the Leech- Gatherer.
- David Elginbrod by George MacDonald