The American Heritage® Dictionary of the English Language: Fourth Edition. 2000.
Appendix I
Indo-European Roots
ENTRY:
bhes-
DEFINITION:
To breathe. Probably imitative. Zero-grade form *bhs-.psyche1, psychic, psycho-; metempsychosis, from Greek pskh, spirit, soul, from pskhein (< *bhs--kh-), to breathe. (Pokorny 2. bhes- 146.)
kh
, spirit, soul, from ps
