fulminant (adj.)

early 15c., "publish a 'thundering' denunciation; hurl condemnation (at an offender)," a figurative use, from Latin fulminatus, past participle of fulminare "hurl lightning, lighten," figuratively "to thunder," from fulmen (genitive fulminis) "lightning flash," related to fulgor "lightning," fulgere "to shine, flash," from PIE *bhleg- "to shine, flash," from root *bhel- (1) "to shine, flash, burn." Metaphoric sense (the oldest in English) in reference to formal condemnation is from Medieval Latin fulminare, used of formal ecclesiastical censures. Related: Fulminated; fulminating.