deleterious
UK: ˌdelɪˈtɪəriəs | US: ˌdelɪˈtɪriəs
adj. harmful or damaging to health or well-being
adj. having a subtle or gradual negative effect
Derived from Greek "deleterios" (destructive), via Latin "deleterius." The root "deleter" traces back to "deleisthai" (to harm), while "-ious" is a common English adjectival suffix indicating "characterized by." The word evolved to describe not just overt destruction but also insidious harm, reflecting its medical and scientific usage in describing slow-acting toxins or chronic effects.
Smoking has deleterious effects on lung function.
The chemical spill caused deleterious changes to the ecosystem.
Prolonged stress can be deleterious to mental health.
The policy had unintended deleterious consequences for small businesses.
Studies show that sleep deprivation is deleterious to cognitive performance.