flagrant

borrowed from Latin flagrant-, flagrans "flaming, fiery, (of a person) burning with desire, passionate," present participle of flagrāre "to be ablaze, burn, shine, burn (with passion, zeal)," probably derivative of an adjective *flagro- "burning," going back to Indo-European *b^hl̥g-ro-, adjective derivative from the verbal base b^hleg- "shine, be bright"; (sense 1) after in flagrante delicto and parallel Latin phrases — more at phlegm

Note: The metaphorical notion of a misdeed as "flaming" when the offender is caught in the act first appears in Latin in the Code of Justinian (sixth century), flagrans being conjoined there with crīmen "crime." Conjoining of flagrans with delictum "misdeed, offense" is perhaps no earlier than the fifteenth century. — The vocalism of flagrāre is traditionally explained as "reduced grade" (German Reduktionstufe, more traditionally schwa secundum "second schwa"), where zero-grade—here *b^hl̥g- as evidenced in Latin fulgēre "to shine brightly" (see fulgent)—is reduced to *b^hl_eg- before the suffix -ro-. P. Schrijver gives the more specific suggestion that a in flagrāre is the regular outcome of the sequence *R̥DC in Italic and Celtic, where R is any resonant, D is a plain voiced stop, and C any consonant (The Reflexes of the Proto-Indo-European Laryngeals in Latin, Rodopi, 1991, pp. 477-85). Examples are few, however. Another possibility is frangere "to break, shatter" (see break entry 1), if the nasal present stem is a later development, and *frag- is the result of *b^hr̥g- plus a consonant (presumably the -t- of nominal derivatives). Alternatively, frang- could be an outcome of *b^hr_eng- in place of *b^hr̥ng-.