fḥḥ, fḫḫ - siffler (se dit des serpents); siffler en dormant (se dit d’un homme) (to whistle (said of snakes); to whistle while sleeping (said of a man)
(BK 2 547, Lane 2348)
PWS
*pḫ/ḥ - to breathe, blow, exhale (smell)
(SED I No. 54ᵥ)
Reconstructed as a biconsonantal root with various ways of triconsonantization (insertion of medial w, doubling of the second radical, etc.).