incompatible
adj
1.
2.
used especially of drugs or muscles that counteract or neutralize each other's effect
3.
4.
incapable of being used with or connected to other devices or components without modification
Antonym:
compatible 5.
of words so related that one contrasts with the other
6.
7.
8.
not in keeping with what is correct or proper
9.
used especially of solids or solutions; incapable of blending into a stable homogeneous mixture