A razor — a blade used for shaving facial or body hair. Often written in kana, though the kanji 剃刀 exists.
毎朝かみそりで髭を剃るのが日課だ。
Shaving my beard with a razor every morning is my routine.
切れ味のいいかみそりの刃に替えてください。
Please replace it with a razor blade that has a good edge.
旅行には安全カバー付きのかみそりを持って行ったほうが安心だ。
It's safer to bring a razor with a protective cover when traveling.