"Burn up" is a versatile phrasal verb predominantly used in informal speech, experiencing a variety of applications in different contexts. In everyday conversational English, it may describe someone experiencing intense heat or fever, as in "You're burning up with fever." Additionally, it can imply extreme anger or frustration, such as "She was burning up about the decision." Its informal nature can extend to having consumed all fuel in the context of vehicles or engines—"The car burned up a lot of gas." It can also refer to the complete destruction by fire, like "The papers burned up in the fireplace." Though usually not used in formal writing, it might appear in creative literature or informal workplace communication to convey urgency or strong emotions. Usage indicates both literal and figurative meanings, depending on context, making it a flexible phrasal verb in English vocabulary.
B1
PreIntermediate
1. To consume something completely by fire.
The campfire burned up all the wood we had collected.
The old documents were burned up in the fire accident.
2. To feel or cause to feel extreme heat or fever.
After running for an hour, I felt like I was burning up.
He’s burning up with a fever; we should take him to the doctor.
3. To feel intense anger or irritation.
She was burning up with anger after hearing the news.
I could see he was burning up, trying to hide his annoyance.