- paranoia
- "mental disorder characterized by systematized delusions," 1891 (earlier paranoea 1811), from Gk. paranoia "mental derangement, madness," from paranoos "mentally ill, insane," from para- "beside, beyond" + noos "mind." Paranoid (adj.) is first attested 1904, from paranoia + Gk. -oeides "like," from eidos "form, shape" (see -oid). The noun meaning "a paranoid person" is attested from 1922.