(Cambridge University slang) A social meal between two university societies (a swap) held at a formal hall; generally less associated with drinking games and rowdy behaviour.

plural of formal swap

(Oxbridge) A formal meal held in a college hall, generally with a grace, waiting staff and a set menu with multiple courses; usually held once or twice per week.

A formalism for a physical theory which is based upon Feynman path integrals.

(mathematics, algebra) Any finite or infinite series of the form a_0+a_1x+a_2x²…=∑ᵢa_ixⁱ, where the aᵢ are numbers, but it is understood that no value is assigned to x.