A "burn" can refer to either an injury caused by heat, fire, radiation, chemicals, or electricity,

 A "burn" can refer to either an injury caused by heat, fire, radiation, chemicals, or electricity, or the act of burning something with fire. It can also describe a sensation of intense heat, or even be used in slang to mean being insulted. 

Here's a more detailed breakdown:

Medical Definition:

A burn is a tissue injury caused by heat, fire, radiation, chemicals, or electricity. 

Burns can range in severity from minor sunburns to deep, tissue-damaging injuries. 

Burns are classified by their depth and severity, with first, second, and third-degree burns being common. 

Other forms of burns include chemical burns, electrical burns, and radiation burns. 

Verbal Definition:

To "burn" can mean to be destroyed by fire or to cause something to be destroyed by fire. 

It can also refer to the act of producing heat or light through combustion, like a burning candle. 

In everyday language, it can also describe a sensation of intense heat or a burning feeling. 

In slang, "burn" can mean to insult or deceive someone. 

Examples:

"I got a sunburn on my back after spending too long in the sun" (medical definition). 

"The factory was completely burned to the ground in the fire" (verb, destruction). 

"That curry has a real burn to it" (sensation of heat). 

"You really burned me with that comment" (slang, insult).