| Kafuffle | Argument; disturbance |
| Kangaroo court | Biased opinions of people judging you |
| Kangaroos loose in the top paddock | Crazy |
| Kark it | Die |
| Keen as mustard | Enthusiastic about something |
| Kick in | Contribute money to something |
| Kick the bucket | Die |
| Kindy | Kindergarden (first year of primary school) |
| Kip | Nap; short rest |
| Kiwi | New Zealander |
| Knackers | Male testicles |
| Knee high to a grasshopper | Small child eg. when I was knee high to a grasshopper |
| Knickers | Female underwear |
| Knock back | Refusal |
| Knock shop | A house of prostitution; whore house |
| Knock something | Criticise it |
| Knock your socks off | Cause amazed admiration |
| Knocked off work | Finished work for the day |
| Knocked up | Pregnant |
| Knock-off | A counterfeit product |
| get Knotted! | Angry way of saying “get lost” |
| Knuckle sandwich | Punch in the mouth |
| pack your Kit | Pack your belongings or possessions |
| A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | PQ | R | S | T | UV | W | XYZ |
