paroxysmal

The word 'paroxysmal' originates from the Greek paroxysmos, meaning a sharpening, irritation, or severe fit, which itself derives from paroxynein ("to sharpen, irritate"), combining para- ("beyond") and oxynein ("to sharpen"). This root meaning of a sudden, sharp intensification passed into medical Latin as paroxysmus to describe a sudden attack or worsening of a disease. The English adjective was formed by appending the Latin-derived suffix -al, meaning "pertaining to," to the noun 'paroxysm.' Thus, the literal construction "pertaining to a sudden sharp attack" evolved into its modern medical and general sense, describing phenomena that occur in sudden, violent spasms or outbursts.

Structure: paroxys (sudden attack) + mal (pertaining to) paroxys (from Greek paroxysmos, meaning "irritation, severe fit") + mal (from Latin -alis, an adjectival suffix meaning "pertaining to")