circular saw 
noun
A power saw with a rapidly rotating toothed disc.Generally, use a handsaw or a circular saw to cut straight lines, a coping saw or a portable jigsaw to cut irregular lines....
- Most cuts can be made with a circular saw, handsaw, or saber saw, but the angled back support would be more easily cut with a table saw.
- It could potentially boost the safety of all power saws, including band saws and circular saws.