Relating to, characterized by, or inclined toward apoplexy or extreme anger; having apoplectic qualities.
From apoplexy with the suffix -ious meaning 'full of' or 'characterized by.' This archaic adjective form appeared in older medical and literary texts.
You'd see 'apoplexious' in old novels to describe a portly gentleman whose face turned crimson with rage—authors loved this word to paint a picture of someone on the verge of a medical catastrophe from sheer fury.
Complete word intelligence in one call. Free tier — 50 lookups/day.