(algebra) An ideal I in an algebraic object R (which could be a ring, algebra, semigroup or lattice) that is generated by a given single element a ∈ R; the smallest ideal that contains a.

(computer security) An entity capable of being authenticated by a computer system or network.

(cinematography) The phase of film production during which the film is actually shot, as distinct from pre-production and post-production.

(mathematics) An ultrafilter such that every set belonging to it is the superset of some fixed singleton set.

(sciences) lead researcher on a grant-funded project

plural of principal investigator

plural of editio princeps

(grammar, usually in the plural) Any of the forms of a word which contain its stem(s) in the simplest form, or such a form that, when taken with all the other principal parts, allows the entire paradigm to be derived.

An assistant principal or deputy headteacher.

plural of vice-principal