- keep the lid on
- keep the pot boiling
- keep time
- keep the wolf from the door
- keep to oneself
- keep under
- kvetch
- kick
- king of the herring
- khadafy
- ki
- khat
- kyzyl kum
- knavery
- kizil kum
- killer T cell
- killer cell
- key
- kooky
- kookie
- kitchen appliance
- kwacha
- kepi
- knuckle
- know the ropes
- kink
- kill
- knell
- kloof
- knackered
- knacker
- knock out
- killing
- knackering
- kind
- kissing the feet (as a mark of deep respect or for flattering)
- kind to the poor
- kindness
- krypton
- Kr
- kept woman
- knockout
- kybosh
- key out
- kin
- kinship system
- kimono
- keratoscleritis
- keratoiritis
- keratoconjunctivitis