intransitive verb
1. : to sink inward
the roof fell in
2.
a. : to come to an end : terminate , lapse — used of a lease or annuity
b. : to come into the owner's possession after a lease
c. : to become operative or available (as of a reversion)
3. obsolete : to rush in or come in
4. archaic : occur , happen
5. : to take one's proper place in a military formation and come to the position of attention
transitive verb
: to cause (troops) to take proper positions in ranks : cause (a military unit) to form ranks
•
- fall in for
- fall in with