Verbs formed from nouns or adjectives (compare English -ate, -ize), frequently having a causative force, or modified from an existing verb into a frequentative verb (no longer productive)

The twentieth letter of the English alphabet, called tee and written in the Latin script.

The ordinal number twentieth, derived from this letter of the English alphabet, called tee and written in the Latin script.

(ratings) Teen. / (finance) Taxable. / American Library Association abbreviation of twentieth, a book size range (12.5-15 cm in height).

(informal) A T-shirt. / Tuesday. / Thursday. / (music) Tenor. / (automotive) The Ford Motor Company's Model T automobile. / (rail transport, in multiple unit formations) Trailer car.

(stock ticker symbol) AT&T.

(archaic or eye dialect) Contraction of it. / (eye dialect) Contraction of that.

(idiomatic) Precisely; exactly; perfectly; with great attention to detail.

(topology, of a topological space) Such that any two points have disjoint neighborhoods.

(of a topological space) Such that, for any two of its points, there exist respective open sets containing each and not the other.