It depends on the exact context, but:
“Trivial” usually means “not important.” For example, a person gets an echocardiogram and the cardiologist reports “trivial regurgitation,” it means the valve is leaking so little that it’s not worth worrying about.
“Naive” means not having experienced that thing. For example, in pain management, there is a distinction between “opioid naive” people, who have not previously had opioids, vs. “opioid tolerant” who have taken opioids long enough that the effects are lower on them. The tolerant group can take higher doses that might put the naive group at risk of death.
TYL that “centrist” is short for “self-centered.”