- Kitten
- Knacker's yard
- Knackered
- Knackers yard
- Knavish
- Knee-breeches
- Knee-deep
- Kneecap
- Kneel down
- Knelt
- Knick knack
- Knife-edge
- Knightly
- Knock about
- Knock off
- Knock the spots off
- Knock-up
- Knockout
- Knot
- Knottiest
- Know a person by name
- Know a thing or two
- Know inside out
- Know ones onions
- Know ones own mind
- Know the place like the back of ones hand
- Know the time of day
- Know what one is talking about
- Knower
- Knuckle
- Knuckle-under
- Kohinoor
- Kohlrabi
- Konganadu
- Kookaburra
- Kowtow
- Kremlin
- Krm
- Kuiper belt
- Kunti
- Kuruksethra
- Kusa grass
- Kw
- Kathakali
- Kali
- Kalian
- Krait
- Kalidasa
- Kaempferia galanga
- Kafka
- Kaim
- Kalanchoe pinnata
- Kaleidoscope
- Kaliya
- Kame
- Kangaroo
- Kannasa panikkar
- Kapok buds
- Kaput
- Kardex
- Karl max
- Karma
- Kashmir
- Kasi
- Kaurava dynasty
- Keel
- Keen eye
- Keenly
- Keenness
- Keep a calm sough
- Keep a good table
- Keep a watch out
- Keep at
- Keep at bay
- Keep at it
- Keep body and soul together
- Keep dark
- Keep house
- Keep morale
- Keep mouth shut
- Keep on a tight rein
- Keep one powder dry
- Keep one's mouth shut
- Kerb crawling
- Keep ones head
- Key flute
- Keep ones temper
- Keep oneself in
- Keep order
- Keep sb up
- Keep step
- Keep the pace
- Keeping bullets
- Keeping prop
- Kelly
- Keloid
- Ken
- Kept
- Kerbstone
- Kerchief