theorem
This term carries a heavy weight of certainty and absolute truth. It is not a guess or a hypothesis, but a conclusion that has been logically locked into place through a rigorous process of proof. Because of this, it is almost exclusively used in the realms of mathematics, logic, and theoretical computer science.
In a social or casual conversation, using this word can sound overly formal or intentionally pedantic. It suggests a level of structural rigidity and undeniable evidence that distinguishes it from a theory, which remains open to revision based on new data.
Countable when referring to individual mathematical laws, such as Fermat's Last Theorem.
Meanings
A statement or proposition that has been proven to be true based on previously established statements.
The Pythagorean theorem describes the relationship between the sides of a right triangle.