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
Word History
First Known Use
1818, in the meaning defined at sense 1
- ink-blot
- ink-jet
- ink-jet printer
- diagenetically
- diageotropic
- diageotropies
- diageotropism
- diageotropisms
- diageotropy
- Diaghilev
- diaglyph
- diaglyphic
- diaglyphs
- diaglyptic
- diagnosable
- diagnose
- diagnoseable
- diagnosed
- diagnoses
- diagnosing
- diagnosis
- diagnosis related group
- diagnostic
- diagnostical
- diagnostically