jackknife (n.)
- adz
- ax
- bushwhacker
- cannonball
- chaser
- chisel
- cleaver
- clipper
- dagger
- dive
- drop
- fall
- gainer
- gouge
- hack
- hatchet
- header
- hoe
- knife
- lance
- lancet
- machete
- mattock
- penknife
- pick
- pickax
- pitch
- plowshare
- plunge
- pounce
- razor
- sax
- scalpel
- scissors
- scoop
- scraper
- scythe
- share
- shears
- sickle
- snips
- spear
- spokeshave
- stoop
- swoop
- sword
- wedge
