Stang's law

Etymology
Named after the Norwegian linguist Christian Stang.

Proper noun

 * 1)  A Proto-Indo-European phonological rule that governs the word-final sequences of a vowel, followed firstly by a semivowel or a laryngeal and then by a nasal. Such sequences are simplified so that laryngeals and semivowels are dropped, with compensatory lengthening of a preceding vowel.