fall behind
US /fɔːl bɪˈhaɪnd/
UK /fɔːl bɪˈhaɪnd/
1.
to fail to keep up with a schedule or progress
:
•
If you don't study regularly, you'll fall behind in your classes.
•
The company started to fall behind its competitors in innovation.
2.
to not pay money that you owe on time
:
•
He started to fall behind on his rent payments.
•
Many small businesses fall behind on their taxes during economic downturns.