Dictionary definition · fall out
verb
- have a breach in relations"We fell out over a trivial question"
- come as a logical consequence; follow logically"It follows that your assertion is false"
- drop out"His hair and teeth fell out"
- leave (a barracks) in order to take a place in a military formation, or leave a military formation"the soldiers fell out"
- come to pass"What is happening?"
Source: Open English WordNet (CC BY 4.0).