(law) Synonym of fireman's rule

A formula used to estimate underlying probabilities when there are few observations, or for events that have not been observed to occur at all in (finite) sample data.

(Canada, crime, law, politics, constitution, human rights) A rule about how long criminal court cases can take, and when exceeding the determined limit, is considered excessive and violating constitutional rights, and thus the criminal proceedings are summarily terminated with no recourse, and the defendant released. The limit of 18 or 30 months from placing criminal charges to trial is established in the rule.

(rare) A flexible leaden mason's rule that can be bent around the curves of a molding, and thus used to measure or reproduce irregular curves.

(geometry) Pythagorean theorem

(games) A rule used in certain strategy games for the purpose of fairness, where immediately after the first player's initial move the opposing player may optionally switch, taking over the first player's role and position for the rest of the game.

(linguistics, phonology, Indo-European studies) A rule of the Proto-Indo-European reconstructed language that states that a labiovelar stop (*kʷ, *gʷ, *gʷʰ) dissimilates to an ordinary velar stop (*k, *g, *gʰ) next to the vowel *u or its corresponding glide *w.

An observation about the early stage of speciation, stating that if in a species hybrid only one sex is inviable or sterile, that sex is more likely to be the heterogametic sex.

(transitive) To draw a line underneath, for example to mark the end of a topic or of an accounting period.

(military, law enforcement, chiefly in the plural) An internal rule among a military, police, etc. force defining the circumstances in which and manner with which to use force.