eat up
With or without an object
Eat all of something
Eat up, children, or your dinner will get cold.
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: up
This verb belongs to the group ‘doing it completely, to the end’.
Practise it
Add it to your daily practice or see every verb with up.
Further reading: eat up on Wiktionary (CC BY-SA).