The Proto-Indo-European word *k̂weshₓ-
Word *k̂weshₓ-
Meaning to breathe, to sigh, to groan
See also Proto-Indo-European: *k̂wéshₓmi ‘to sigh, to breathe deeply’
Synonyms *pneu-, *dhwes-, *dhwésmi

Comments
Mallory J.P. and Adams D. (2006)

Other words that might be of interest
*ses- ‘to rest, to sleep, to keep quiet’