Slice off
Definition 1 of 1
Pro Tip 1/3Physical Action
Used when someone physically cuts something with a motion similar to slicing. 
The chef sliced off the fish's fins before cooking.
Pro Tip 2/3Precision Needed
Implies the need for accuracy, often used for cutting items with precision. 
He carefully sliced off a thin piece of the cucumber for the salad.
Pro Tip 3/3Deliberate Removal
Indicates intentional removal of a part from the whole, not by accident. 
She sliced off the moldy part of the cheese before eating it.