Below are the words that matched your query...
Underground
- conducted with or marked by hidden aims or methods; "clandestine intelligence operations"; "cloak-and-dagger activities behind enemy lines"; "hole-and-corner intrigue"; "secret missions"; "a secret agent"; "secret sales of arms"; "surreptitious mobilization of troops"; "an undercover investigation"; "underground resistance"
- under the level of the ground; "belowground storage areas"; "underground caverns"
- beneath the surface of the earth; "water flowing underground"
- in or into hiding or secret operation; "the organization was driven underground"
- an electric railway operating below the surface of the ground (usually in a city); "in Paris the subway system is called the `metro' and in London it is called the `tube' or the `underground'"
- a secret group organized to overthrow a government or occupation force
Under-The-Table
- designed and carried out secretly or confidentially; "a sub-rosa report"; "has their under-the-table backing"
Under Wraps
- kept secret; "the plan was kept carefully under wraps"
Unpaid
- not paid; "unpaid wages"; "an unpaid bill"
- engaged in as a pastime;
- without payment; "the soup kitchen was run primarily by unpaid helpers"; "a volunteer fire department"
Uncompensated
- not paying a salary; "an uncompensated federal post"
Unsalaried
- not paying a salary; "an uncompensated federal post"
Unpainful
- not accompanied by pain sensations; "pain-free surgery"
Unpainted
- not having a coat of paint or badly in need of a fresh coat; "an unpainted house"; "unpainted furniture"
- not having makeup on; "her sweet unpainted face"