Words and Proper Names

lenition

1627.
Harvey (Anthony): Aspects of lenition and spirantization.
In CMCS 8 (Winter, 1984), pp. 87–100.
Development in Celtic languages. Cf. D. Greene, Gemination, in Celtica 3 (1956), pp. 284-289; The spirant mutation in Brythonic, in Celtica 7 (1966), pp. 116-119; K. H. Jackson, Gemination and the spirant mutation, in Celtica 5 (1960), pp. 127-134.