an instrument that is used for shaving 剃须刀；刮脸刀
an electric razor
电动剃须刀
a cut-throat/safety/disposable razor
开式／安全／一次性剃刀
be on a razor / razor’s edge, [BrE] to be in a difficult position where a mistake could be dangerous
:
Politically we are on a razor edge.
我们在政治上处于险境。