- The definition of deleterious is something that is harmful or damaging.
An example of deleterious is how smoking can kill a human being.
Origin of deleteriousClassical Greek dēlētērios ; from dēlēter, a destroyer ; from dēleisthai, to injure ; from Indo-European base an unverified form del-, to split
Origin of deleteriousFrom Greek dēlētērios, from dēlētēr, destroyer, from dēleisthai, to harm.
(comparative more deleterious, superlative most deleterious)
- harmful often in a subtle or unexpected way (as for example deleterious effects, deleterious to health).
From Ancient Greek δηλητήριος (dēlētērios, “noxious, deleterious”), from δηλητήρ (dēlētēr, “a destroyer”), from δηλέομαι (dēleomai, “I hurt, damage, spoil, waste”).