Of a fire: violent. Obsolete.

Originally (of a fire or flame): burning strongly (now somewhat archaic). In later use (chiefly of an oven): that provides a strong flame; hot. Also…

Of a fire: burning vigorously; roaring. Now chiefly U.S.

Of movement, activity, or something moving or active: having considerable force. Of fire, heat, an internal process, etc.: intense, energetic…

Sharp or smart in regard to movement (in a praiseworthy sense) quick and active, lively. of wind, fire, etc.