Relating to apoplexy (stroke), or describing someone who is extremely angry and red-faced, as if about to have a stroke.
From apoplexy, derived from Greek apoplassein 'to strike down' (apo- 'away' + plassein 'to strike'). The term originally described the medical condition but evolved to metaphorically describe extreme anger.
People used 'apoplectic' way more in Victorian times to describe folks who got so furiously angry they looked like they might have a stroke—their faces would turn purple, their veins would bulge—so doctors literally thought anger could cause those sudden brain attacks.
Complete word intelligence in one call. Free tier — 50 lookups/day.