(logic, mathematics) One of two theorems in mathematical logic that demonstrates the inherent limitations of every formal axiomatic system containing basic arithmetic.

(mathematics) A mathematical statement of some importance that has been proven to be true. Minor theorems are often called propositions. Theorems which are not very interesting in themselves but are an essential part of a bigger theorem's proof are called lemmas.

(transitive) To formulate into a theorem.

Used other than figuratively or idiomatically: see group, theory; a theory about (particular kinds of) groups.

Of or relating to theory; abstract; not empirical.

Of or relating to theology.

One who studies theology. / In Roman Catholic usage, a theological lecturer attached to a cathedral church. / In Eastern Orthodox usage, a person who has had direct experience of and unity with God.

(mathematics) Of, relating to or using set theory.

(chemistry) An obsolete scientific theory of combustion.

(mathematics) Relating to or using graph theory.