Added 10 October 2026
deleterious
/ˌdɛl.ɪˈtɪə̯.ɹi.əs/ adjective
Latin root: dēlētērius Wiktionary
adjective Definition from Wiktionary (CC BY-SA). Pronunciation from Wiktionary, via Kaikki.org. More about deleterious at Wordnik → Where our words come from →
Origin
Adapted borrowing (1640s; 1582 as deletorious) of New Latin dēlētērius, dēlētōrius + -ous, from Ancient Greek δηλητήριος (dēlētḗrios, “noxious, deleterious”), from δηλητήρ (dēlētḗr, “a destroyer”), from δηλέομαι (dēléomai, “I hurt, damage, spoil, waste”). Not related to delete or deleble. Doublet of deletery.
From Wiktionary, via Kaikki.org (CC BY-SA)