the world > movement > motion in a certain direction > going or coming out > letting or sending out > [noun] > letting out (5)
(a) the action or an act of leasing something to a person; (b) the action or an act of releasing something; a pouring forth.
The action or process of letting out; a pouring forth, emission. Frequently figurative.
The action of letting out or discharging something; outflowing (literal and figurative). Obsolete.