phonology

fonologia puhekieltä The study of the way sounds function in languages, including phonemes, syllable structure, stress, accent, intonation, and which sounds are distinctive units within a language.
puhekieltä The way sounds function within a given language.
1856, Journal of the Indian Archipelago and Eastern Asia, Mission Press, page 16:

The Achean, the ancient Malayu and other mixed phonologies possessing a considerable degree of harshness, were thus formed.

Crucially, the neat separateness of phonologies which my account seems to imply is an abstraction and does not mean that the phonologies represented different regional or social dialects.

Thus, underlying ‘agtus’ was converted first into ‘āgtus’ by the vowel lengthening rule, and then into ‘āktus’ by the ancient persistent rule. This example has previously been interpreted as indicating that new rules can enter a phonology elsewhere than at depth I.