The phrase "pizza cutter" refers to a small tool used specifically for cutting pizza. It is a circular blade attached to a handle that makes it easy to slice pizza into individual portions. Full definition
Using pizza cutter or knife, trim dough into a 9 x 9 inch square and then cut the square into nine 3 x 3 inch squares. (atreatsaffair.com)
Without even really trying, this little pizza cutter made the perfect line, and I couldn't get enough. (health.com)
First, it's a wheel style pizza cutter with a sharp, stainless steel blade that rolls over your pizza and cuts it into perfect slices. (geekwrapped.com)