(number theory) The function that counts how many integers below a given integer are coprime to it.

(idiomatic, engineering) A quantity introduced to compensate for uncertainty. / (idiomatic) Any padding or compensation built into a guess or estimate.

(chiefly uncountable) A type of very sweet candy or confection, usually made from sugar, butter, and milk or cream. / (US) Chocolate fudge. / (uncountable) Light or frothy nonsense.

(intransitive) To try to avoid giving a direct answer. / (transitive) To alter something from its true state, as to hide a flaw or uncertainty, deliberately but not necessarily dishonestly or immorally.

(colloquial, minced oath) Used in place of fuck. / (colloquial, archaic) Nonsense; tommyrot.

An opening in the ground that emits steam and gases due to volcanic activity.

Britain standard spelling of fulfill.

To satisfy, carry out, bring to completion (an obligation, a requirement, etc.). / To emotionally or artistically satisfy; to develop one's gifts to the fullest.

The act of fulminating or exploding; detonation. / The act of thundering forth threats or censures, as with authority. / That which is fulminated or thundered forth; vehement menace or censure.

The act of fumigating, or applying smoke or vapor, as for disinfection. / Vapor raised in the process of fumigating.