Wiktionary
vb. 1 (context intransitive English) To collapse inwards. 2 (context intransitive military English) Of a soldier, to get into position in a rank. 3 To come to an end; to terminate; to lapse. 4 To become operative.
WordNet
v. break down, literally or metaphorically; "The wall collapsed"; "The business collapsed"; "The dam broke"; "The roof collapsed"; "The wall gave in"; "The roof finally gave under the weight of the ice" [syn: collapse, cave in, give, give way, break, founder]
to take one's place in a military formation or line; "Troops fall in!"
become part of; become a member of a group or organization; "He joined the Communist Party as a young man" [syn: join, get together]
Wikipedia
Fall In is a 1942 American comedy film directed by Kurt Neumann and written by Eugene Conrad and Edward E. Seabrook. The film stars William Tracy, Joe Sawyer, Robert Barrat, Jean Porter and Arthur Hunnicutt. The film was released on November 20, 1942, by United Artists.
Usage examples of "fall in".
In fact, some had vowed vengefully that there would come the day when Nick Markov would fall in love with a woman, and fall hard, and if there was any justice, she would show him just what it felt like to have that feeling be one-sided.
Hendry gave it as his opinion that the ship will fall in the Pacific Ocean.
The Astronomer Royal had announced that the rocket would fall in the Pacific, and fall in the Pacific she would.