also knife edge
1.
To be on a knife-edge means to be in a situation in which nobody knows what is going to happen next, or in which one thing is just as likely to happen as another. ( mainly BRIT )
The game is poised on a knife-edge. One mistake or one piece of good luck could decide it.
PHRASE : oft v-link PHR
2.
You can use knife-edge to refer to something that is very exciting or tense because you do not know what is going to happen next. ( mainly BRIT )
Tonight’s knife-edge vote could be uncomfortably close.
ADJ : ADJ n