Lenis

Lenis is a term used in linguistics to describe a class of consonants that are relatively lax or weak in articulation, in contrast with fortis consonants, which are considered strong or tense. The distinction lenis–fortis is a descriptive device used in some phonological analyses to capture contrasts in certain languages between more forceful and less forceful obstruents.

In languages that employ a fortis–lenis contrast, lenis consonants are often associated with lower tenseness and may include voiced or less aspirated realizations, whereas fortis consonants tend to be more forceful, frequently voiceless or highly aspirated, and sometimes longer. However, the exact phonetic realization of the two classes varies by language, and there is no universal mapping between lenis and specific phonetic features such as voicing or aspiration. Some languages align lenis with voiced or weakly aspirated segments, while others may treat fortis as the clearly aspirated or voiceless set.

The concept functions as a property of consonants (stops, fricatives, and affricates) rather than as a separate phoneme in itself. It helps explain certain phonological patterns, such as alternations driven by tenseness, historical sound changes, and morpheme boundaries. The term derives from Latin lenis meaning soft or gentle, reflecting the idea of reduced articulatory effort compared to fortis.

In summary, lenis is a descriptive label for a subset of consonants characterized by relatively relaxed articulation, used in contrast with fortis in phonological analyses of languages that exhibit a tenseness-based contrast.