(cryptography) The idea that a cryptosystem should be designed to be secure even if everything about the system, except the secret key, is public knowledge.

(philosophy, rhetoric) The principle according to which an argument should be evaluated in light of its best, strongest possible interpretation.

(sociolinguistics) The idea that listeners and speakers need to cooperate in order to communicate effectively.

plural of agreement in principle

Alternative form of non-aggression principle

(evolutionary biology) The hypothesis that the phylogeny which includes the fewest character changes is the one most likely to be correct.

(somewhat derogatory) A policy that prohibits building anything that could disturb those who already reside in an area.

(linguistics) The idea of using ideograms as phonograms representing the sounds of the words expressed by the original ideograms.

(physics) the principle that classical physics is the limit of quantum physics as quantum numbers approach infinity

(UK, education) The idea that university places should be available to everybody who qualifies for them by ability and attainment.