break off
With or without an object
Separate a piece by breaking, or stop suddenly
She broke off a piece of chocolate and shared it.
End a relationship or talks
They broke off the engagement last spring.
With or without an object
It can be used with no object, and it can also take one. With an object it is usually separable: turn the volume up, turn it up.
The particle: off
This verb belongs to the group ‘cutting and separating’.
Practise it
Add it to your daily practice or see every verb with off.
Further reading: break off on Wiktionary (CC BY-SA).