| guileful(adjective, dishonest, cunning, deceitful, sneaky) |
| hidden(adjective, secret, private, spy, underground) |
| hole-and-corner(adjective, secret, private, hidden, spy) |
| in ambush(expression, adjective, close, sensitive, clandestine) |
| incognito(adjective, close, secret, hidden, spy) |
| indirect(adjective, dishonest, cunning, deceitful, crooked) |
| inside(adjective, close, clandestine, underground, undisclosed) |
| lubricious(adjective, dishonest, cunning, fickle, untrustworthy) |
| oblique(adjective, dishonest, cunning, deceitful, crooked) |
| on the QT(expression, adjective, idiom, sensitive, dishonest) |
| on the quiet(expression, adjective, idiom, dishonest, cunning) |
| on the sly(expression, adjective, idiom, private, hidden) |
| private(adjective, secret, hidden, spy, sneak) |
| restricted(adjective, secret, clandestine, underground, undisclosed) |
| scheming(adjective, sneaky, covert, secretive) |
| secretive(adjective, dishonest, deceitful, clandestine, sneaky) |
| shady(adjective, dishonest, cunning, deceitful, crooked) |
| shifty(adjective, dishonest, cunning, deceitful, sneaky) |
| skulking(adjective, secret, private, hidden, sneaky) |
| slinking(adjective, secret, private, hidden, sneaky) |