Lenition

Lenition is a phonological process in which a consonant becomes less constricted or otherwise weaker. It occurs in patterns shaped by sound context, word position, or grammar.

Voicing: Voicing is vibration of the vocal folds during speech sound production. A voiceless consonant may become voiced as one form of lenition.
Phonetics: Phonetics is the study of speech sounds and their physical production, transmission, and perception. Lenition is often described through changes in articulatory constriction.
Celtic mutation: Celtic mutation is a set of initial consonant alternations conditioned by grammatical and lexical contexts in Celtic languages. Lenition is a prominent type of mutation in several Celtic languages.
Romance languages: The Romance languages descend from spoken forms of Latin. Many Romance varieties preserve historical intervocalic lenition in their consonant systems.
Spirantization: Spirantization changes a stop consonant into a fricative or approximant. It illustrates weakening through a less complete oral closure.
Phonology: Phonology is the study of how languages organize speech sounds into patterns and systems. Lenition is a patterned sound process rather than simply a physical gesture.
Irish phonology: Irish phonology is the sound system and sound-patterning of the Irish language. Irish uses initial lenition in grammatical contexts and marks it in spelling.
Latin: Latin was the language of ancient Rome and the ancestor of the Romance languages. Changes from Latin consonants help explain lenition patterns in Romance.
Debuccalization: Debuccalization replaces an oral consonant with a sound produced at the glottis. It can weaken a consonant by removing its oral place of articulation.
Consonant: A consonant is a speech sound produced with some constriction or closure in the vocal tract. Lenition specifically changes consonants and their degree of constriction.

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