- Noun. The act or process of falling in.
- Noun. An incursion; an inroad.
- Noun. (countable) The area where water, storm runoff, etc., enters a stormdrain.
- Noun. (context, astronomy) 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. (intransitive) To fall in.
- Verb. (intransitive, astronomy) To undergo infall.