Lenition

In linguistics, lenition is a kind of sound change that alters consonants, making them more sonorous (vowel-like). The word lenition itself means "softening" or "weakening" (from Latin lenis = weak). Lenition can happen both synchronically (i.e. within a language at a particular point in time) and diachronically (i.e. as a language changes over time). Lenition can involve such changes as making a consonant more sonorous, causing a consonant to lose its place of articulation (a phenomenon called debuccalization, which turns a consonant into a glottal consonant like [h] or [ʔ]), or even causing a consonant to disappear entirely.