| lock horns | | | |
| lone it | | | |
| long arm of the law | | | |
| long green | | | |
| long in the tooth | | | |
| long screwdriver | | | |
| long story short | | | |
| look ahere | | | |
| look before one leaps | | | |
| look for number one | | | |
| look-in | | | |
| look on the bright side of it | | | |
| look out for number one | | | |
| look through | | | |
| look up and down | | | |
| loose end | | | |
| loosen someone's lips | | | |
| lord it over | | | |
| Lord's Supper | | | |
| lose it | | | |
| lose one's head | | | |
| lose one's shit | | | |
| lose one's virginity | | | |
| lose the bubble | | | |
| loss of face | | | |
| lost in translation | | | |
| louse up | | | |
| love goggles | | | |
| love of one's life | | | |
| lower the boom | | | |
| low road | | | |
| luck out | | | |
| lucky dog | | | |
| lump to one's throat | | | |
| labour the point | | | |
| laced mutton | | | |
| ladies' man | | | |
| lady or tiger | | | |
| landing strip | | | |
| land of opportunity | | | |
| land on one's feet | | | |
| land the plane | | | |
| large and in charge | | | |
| last-ditch | | | |
| last hurrah | | | |
| last minute | | | |
| last of the big spenders | | | |
| last roundup | | | |
| Last Supper | | | |
| last thing one needs | | | |
| last word | | | |
| late model | | | |
| lathered up | | | |
| laugh a minute | | | |
| laughing tackle | | | |
| laugh one's head off | | | |
| laugh up one's sleeve | | | |
| lay a finger on | | | |
| lay an egg | | | |
| lay by the heels | | | |
| lay down the marker | | | |
| lay eyes on | | | |
| lay it on | | | |
| lay odds | | | |
| lay of the land | | | |
| lay one's head | | | |
| lay on the line | | | |
| lay something at the feet of | | | |
| lay the groundwork | | | |
| lay to rest | | | |
| lead by the nose | | | |
| leading light | | | |
| lead on | | | |
| lead someone up the garden path | | | |
| lead time | | | |
| lead with one's chin | | | |
| leaps and bounds | | | |
| learned profession | | | |
| learn to walk before one can run | | | |
| leather-lunged | | | |
| leave a sour taste in one's mouth | | | |
| leave behind | | | |
| leave home | | | |
| leave it alone | | | |
| leave it be | | | |
| leave no stone unturned | | | |
| leave on | | | |
| leave someone high and dry | | | |
| leave someone in the dust | | | |
| leave someone no choice | | | |
| leave someone to their fate | | | |
| leave something to be desired | | | |
| leave the door open | | | |
| leave things alone | | | |
| leave to the imagination | | | |
| left turn | | | |
| legal duty | | | |
| legend in one's own lunchtime | | | |
| lend a hand | | | |
| lend itself to | | | |