| ugly customer |
| ugly duckling |
| under construction |
| under control |
| under lock and key |
| under no circumstances |
| under one's own steam |
| under one's thumb |
| under sail |
| under someone's nose |
| under the covers |
| under the gun |
| under the impression |
| under the influence |
| under the radar |
| under the rose |
| under the sheets |
| under the sun |
| under the wire |
| under way |
| unicorn puke |
| unicorn vomit |
| unknown quantity |
| unload |
| unplug |
| unring a bell |
| until one is blue in the face |
| until the cows come home |
| unto the ages of ages |
| unused to |
| up a gum tree |
| up a height |
| up-and-comer |
| up and coming |
| up and running |
| up a tree |
| up front |
| up hill and down dale |
| up on |
| up one's own ass |
| upon the instant |
| upon the tapis |
| upper hand |
| upper storey |
| upset the applecart |
| up shit creek without a paddle |
| up someone's street |
| up the ante |
| up the river |
| up the wall |
| up-to-date |
| up to eleven |
| up to one's ears |
| up to one's neck in alligators |
| up to speed |
| up to the hub |
| up with the larks |
| urban fabric |
| use in anger |
| useless as tits on a boar hog |
| ugly American |
| under a cloud |
| under a spell |
| under erasure |
| under glass |
| under one roof |
| under one's hat |
| under one's very eyes |
| under one's wing |
| understand the assignment |
| under the carpet |
| under the hammer |
| under the illusion |
| under the mahogany |
| under the microscope |
| under the rug |
| under the saya |
| under the surface |
| under the weather |
| undress with one's eyes |
| unicorn barf |
| university of life |
| university of the streets |
| unmask one's batteries |
| uno ab alto |
| unsung hero |
| until hell freezes over |
| until the cows freeze over |
| until the last dog is hung |
| up against |
| up against it |
| up and at 'em |
| up and away |
| up-and-coming |
| up and down |
| up for |
| up for grabs |
| uphill battle |
| up in the air |
| up one's sleeve |
Mac + Safari
iPhone + iPad
Google Chrome
Mozilla Firefox
Opera
Microsoft Edge