| on the quiet(expression, idiom, fickle, untrustworthy, unprincipled) |
| perjurious(fickle, untrustworthy, unprincipled, dirty-dealing) |
| polygamous(fickle, untrustworthy, unprincipled) |
| protestant |
| quicksilver(fickle, untrustworthy, unprincipled, dirty-dealing) |
| recreant(adjective, false, dishonest, dubious, untrustworthy) |
| sinful |
| snake in grass(expression, idiom, fickle, untrustworthy, unprincipled) |
| stop-at-nothing(fickle, untrustworthy, unprincipled, dirty-dealing) |
| stop at nothing(expression, idiom, fickle, untrustworthy, unprincipled) |
| sub-rosa(fickle, untrustworthy, unprincipled, dirty-dealing) |
| treasonable(fickle, untrustworthy, unprincipled, dirty-dealing) |
| treasonous(fickle, untrustworthy, unprincipled, dirty-dealing) |
| trustless(fickle, untrustworthy, unprincipled) |
| two-faced(adjective, false, dishonest, dubious, untrustworthy) |
| unassured(fickle, untrustworthy, unprincipled) |
| unconsenting |
| under cover(expression, fickle, untrustworthy, unprincipled, dirty-dealing) |
| underhand(fickle, untrustworthy, unprincipled, dirty-dealing) |
| undutiful(fickle, untrustworthy, unprincipled, dirty-dealing) |