infall

noun

1. (countable, uncountable)The act or process of falling in.
2. (countable, uncountable)An incursion; an inroad.

   “1650, Oliver Cromwell, a letter we learn that Ker , with his Western Army , was lying at a place called Carmunnock , when he made this infall upon Lambert”

3. (countable)The area where water, storm runoff, etc., enters a storm drain.
4. (uncountable)Movement towards a massive astronomical body under the influence of gravity; especially the process whereby gas falls towards a neutron star or black hole at high speed, forming a plasma

verb

1. (intransitive)To fall in.
2. (intransitive)To undergo infall.

   “After this time the beam mass loss rate decreases since once the expansion wave radius is larger than the beam, material initially outside the beam starts to infall and compensate for material which is collapsing at centre of the core [...]”