| artful(hidden, sly, fraudulent) |
| by stealth(expression, clandestine, quietly, secretly, personally) |
| clandestine(adjective, secret, sly, secretly, slyly) |
| clandestinely(clandestine, quietly, secretly, personally, privately) |
| cloak-and-dagger(hidden, sly, fraudulent) |
| closet(hidden, sly, fraudulent) |
| covertly(quietly, secretly, personally, privately, furtively) |
| foxy(hidden, sly, fraudulent) |
| furtively(clandestine, quietly, secretly, personally, privately) |
| hush-hush(clandestine, quietly, secretly, personally, privately) |
| illegitimate(hidden, sly, fraudulent) |
| illicit(hidden, sly, fraudulent) |
| in camera(expression, clandestine, quietly, secretly, personally) |
| in confidence(expression, quietly, secretly, personally, privately) |
| in strict confidence(expression, idiom, quietly, secretly, personally) |
| insidiously(quietly, secretly, personally, privately, furtively) |
| intimately(quietly, secretly, personally, privately, furtively) |
| obscurely(quietly, secretly, personally, privately, furtively) |
| on the QT(expression, idiom, clandestine, quietly, secretly) |
| on the quiet(expression, idiom, clandestine, quietly, personally) |