Government by violent gangs, or by the masses.

(idiomatic) A fundamental rule or principle. / (ethics) The principle that one should treat other people in the manner in which one would want to be treated by them.

(chemistry) A rule stating that atoms lose, gain, or share electrons in order to have a full valence shell of 8 electrons. (Hydrogen is excluded because it can hold a maximum of 2 electrons in its valence shell.)

(law) A test of criminal insanity by which "it must be clearly proved that, at the time of committing the act, the party accused was labouring under such a defect of reason, from disease of the mind, as not to know the nature and quality of the act he was doing, or, if he did know it, that he did not know he was doing what was wrong".

(sports) A rule that ends a one-sided contest prior to its natural conclusion.

A general guideline, rather than a strict rule; an approximate measure or means of reckoning based on experience or common knowledge. / (attributive, usually hyphenated) Approximated, guesstimated.

plural of unspoken rule

plural of unwritten rule

An unspoken rule.

A rule that is understood to apply but does not exist in written form.