knife-edge

noun

ˈnīf-ˌej 

1

: a sharp wedge of steel or other hard material used as a fulcrum for a lever beam in a precision instrument

2

: a sharp narrow knifelike edge

Examples of knife-edge in a Sentence

Recent Examples on the Web

When a boat is balancing on the absolute knife-edge of foiling flight in light air, the priorities change massively, and this is when Fletcher is grateful for the extra help from the booth. — Andrew Rice, New York Times, 15 Sep. 2026

The intriguing twist here, of course, is that humanity's existence is briefly on a knife-edge, as Pike makes the biggest decision of his (or, indeed, anyone's) life. — Richard Edwards, Space.com, 23 July 2026

It’s made from washable cotton for easy cleaning, and has a crisp knife-edge finish for an even sleeker look. — Michelle Baricevic, PEOPLE, 9 June 2026

Starmer’s premiership is on a knife-edge this week as a significant number of Labour Party MPs have openly mutinied, calling for the PM to resign immediately, or to set out a timetable for his departure. — Holly Ellyatt, CNBC, 12 May 2026

Word History

First Known Use

1818, in the meaning defined at sense 1

Rhymes for knife-edge

• allege
• straightedge
• dredge
• edge
• hedge
• ledge
• pledge
• sedge
• sledge
• wedge

Kids Definition

knife-edge

noun

ˈnī-ˌfej

: a sharp wedge usually of steel used as a support for a lever beam in a very exact instrument (as a balance)