Xi
Glossary: xi 息, 'breath' — the fourth and finest of the Xiao Zhiguan's four breath types, 'as if present, as if absent'; the target state of tiaoxi and the bridge word to taixi.
Xi (息, xī) — “breath,” and specifically, in the meditative vocabulary, the finest of the four breath types named by the Xiao Zhiguan: after wind (audible, labored), panting (noisy), and qi (silent but ordinary), comes 息 — the “rest” breath, fine and continuous, “as if present, as if absent.” It is the target state of tiaoxi and the bridge word to taixi: the same character 息 sits at the heart of 胎息 (“embryonic breathing”), the tradition’s name for the breath become so interior it seems to need no nose or mouth.
Usage note: 息 also means “to rest, to cease” (休/息) — and the Zhuangzi’s “the true person breathes from the heels” (真人之息以踵) uses the noun at full depth: breath as the whole-body resting movement. The character’s two senses (breath and rest) are not an accident in this tradition: the finest breath is the resting breath. This site renders it “rest breath” inside the four-breath ladder and plain “breath” elsewhere, so the ladder’s technical sense stays visible.
Sources
- Zhiyi, Xiao zhiguan, breath section: the four types — wind (风), panting (喘), qi (气), rest (息); the rest breath is 'as if present, as if absent'
- Zhuangzi ch. 6: 'the true person breathes from the heels' (真人之息以踵)