/li nish"euhn/ , n.
1. Phonet. a phonological process that weakens consonant articulation at the ends of syllables or between vowels, causing the consonant to become voiced, spirantized, or deleted.
2. Ling. a type of Celtic mutation that derives historically from phonological lenition.
[ 1535-45 for obs. sense "mitigation, assuaging"; 1910-15 for current senses; lenit ( us ) (ptp. of lenire to soften; see LENIS, -ITE 2 ) + -ION ]