(phonology) A rule that describes historical sound change (the change in pronunciation of a given sound or cluster of sounds) in the development of a language.

A relationship in physical chemistry stating that the total enthalpy change during the complete course of a reaction is the same whether the reaction is made in one step or in several steps.

cyberlaw

A fundamental law describing the topology of two-dimensional structures such as biological cells.

The legal system of Ancient Rome. / The legal system applied in most of Western Europe until the end of the 18th century.

(linguistics) A rule according to which the increase of a linguistic construct results in a decrease of its constituents, and vice versa: for example, the more clauses appear in a sentence, the shorter those clauses are.

(phonology) A Common Slavic accent law, according to which Slavic words have a circumflex on the root vowel (i.e. the first syllable) if that word had a mobile accent paradigm in Proto-Slavic and Proto-Balto-Slavic, regardless of whether the root had the Balto-Slavic acute register.

The cynical observation that no scientific discovery is named after its original discoverer.

international law

(historical) A law providing for the support of paupers at the public expense.