Tang-Song reading; tōsō-on
A category of on'yomi (Sino-Japanese reading) based on Chinese pronunciations from the Tang and Song dynasties and later, distinct from go-on and kan-on. Used in linguistic and historical contexts.
See also: 唐音 (とうおん)
The Tang-Song reading of 行 in 行灯 is 'an'.
Tang-Song readings are often found in Zen Buddhist terminology.