subreptive
/sʌbˈriptɪv/Definitions
1. noun
A person or thing that subverts, often in a subtle or insidious manner.
“The corrupt politician was accused of being a subreptive influence on the government.”
2. adjective
Tending to subvert or undermine, often in a subtle or insidious manner.
“The subreptive forces at work in the novel threatened the stability of the entire society.”