The branch of mathematics that deals with the relationships between the sides and angles of (in particular) right-angled triangles, as represented by the trigonometric functions, and with calculations based on said relationships.

trigononnoun

A small triangular harp.

trigonotarbidnoun

Any a group of extinct arachnids (order Trigonotarbida) of the late Silurian and early Permian periods, resembling spiders but without silk-producing spinnerets.

trigonousadj

trigonal; triangular

trigonouslyadv

In a trigonous manner.

trigpointingnoun

The recreational activity of searching for trigpoints.

trigramnoun

A trigraph, a sequence of three letters representing one phoneme.

trigraphnoun

A specific sequence of three letters, especially one used collectively to represent a single phoneme.

trigsnoun

Triglycerides.

triguttulateadj

Having three guttules.

trihalidenoun

Any halide or organohalide having three halogen atoms.

trihalomethanenoun

Any of many halogenated derivatives of methane containing three (not always the same) halogen atoms; many are environmental pollutants

triharmonicadj

Describing a class of sixth-order partial differential equations which arises in areas of continuum mechanics

trihedraladj

Having three plane faces that meet at a common point

trihedronnoun

A geometric figure composed of three planes meeting at a single vertex.

trihelicaladj

Relating to or composed of three helices.

trihelixnoun

Any of a family of transcription factors found in Arabidopsis and other organisms

trihemenoun

Three heme groups in a hemoprotein

trihemeraladj

Relating to a period of three days.

trihemiobolnoun

A coin worth one-and-a-half obols.

triheptadecanoinnoun

The triglyceride of heptadecanoic acid

triheptanoinnoun

The triglyceride of heptanoic acid

triheteromernoun

A trimer composed of three different monomers

triheteromericadj

Having, or relating to, three different types of subunits.

trihexnoun

A polyhex composed of three hexagons

trihexagonaladj

Pertaining to a semiregular tiling of the Euclidean plane with two triangles and two hexagons alternating on each vertex.

trihexosenoun

Any trisaccharide derived from three hexose moieties

trihexosidasenoun

Any enzyme that catalyzes the breakdown of a trihexoside, and often, more specifically, alpha-galactosidase (ceramide trihexosidase), a deficiency of which allows globotriaosylceramide (ceramide trihexoside) to accumulate in the tissues of people with Fabry disease.

Spelling & Dictionary Insight

The English alphabetical index for the letter T contains 27,828 headwords drawn from our Wiktionary-derived dictionary table. At 50 entries per page the browse splits into 557 pages, and you are currently viewing page 445. Every row above is a dictionary-backed entry with a canonical slug, and each links through to a full definition page with pronunciation, senses, etymology, and related-word data where available.

On this page 50 of 50 entries carry a part-of-speech tag and 50 carry at least one stored definition. Coverage varies across letters because Wiktionary volunteers build entries at different speeds for different parts of the alphabet, letters with common starting sounds (S, C, T, P) usually have the densest coverage, while less frequent starters (X, Q, Z) tend to have shorter but more specialised lists. PlainSpell surfaces whatever data is present and links back to the source when a definition is not yet recorded.

For readers using this index as a spelling reference, the guarantee is that every form you see on the list is a documented English headword, not a guess, not a derived inflection lacking a lemma row. If a word you expected to find is absent from the "T" list, it usually means the form exists only as an inflection of another lemma (e.g. a past participle stored under the infinitive) or the entry has not yet been imported from Wiktionary. Use the search bar or the misspelling lookup to resolve these cases.