Definition of the word flare up

The phrase "flare up" originated in the late 1800s and was initially used in reference to a fire that suddenly intensified or rekindled. The term "flare" itself can be traced back to the early 19th century and was originally used to describe a sudden, bright explosion of light, typically caused by a burning substance. In a literal sense, the phrase "flare up" would have originally referred to a fire, such as a campfire or forest fire, abruptly becoming more intense, potentially due to wind or other external factors. However, the expression soon came to be more widely used, particularly in a figurative sense, to describe any instance where an existing issue or disagreement suddenly intensifies, often without any clear cause or explanation. In this broader context, "flare up" could be applied to a number of different situations, such as an argument between friends, a disagreement between colleagues at work, or a sudden escalation in tensions related to a political or social issue. As the term has fallen into common usage, it has also been subject to various adaptations and derivatives, such as "smoldering" (a term used to describe a low-intensity or simmering underlying issue, much like the slow-burning smoke before a fire becomes more intense), and "flare-proof" (which is used to describe materials or objects that are resistant to sudden, intense flare-ups). In summary, "flare up" can be traced back to its original use in relation to fire, but has since become a more broadly used term that describes situations where conflict, tension, or anger suddenly become more intense or apparent, much like the appearance of a bright, fiery explosion of light.