1.
If something such as a person’s hair or a tooth falls out, it comes out.
Her hair started falling out as a result of radiation treatment.
PHRASAL VERB: V P
2.
If you ~ with someone, you have an argument and stop being friendly with them. You can also say that two people ~.
She fell out with her husband...
Mum and I used to ~ a lot.
PHRASAL VERB: V P with n, pl-n V P
3.
see also fallout