what does flash in the pan mean?

FLASH IN THE PAN as NOUN

Meaning
- someone who enjoys transient success but then fails
Hypernyms(s) flash in the pan is a kind of… Example: animal is a hypernym of mammal, plant is a hypernym of flower
- failure (what does failure mean?)
- loser (what does loser mean?)
- nonstarter (what does nonstarter mean?)
- unsuccessful person (what does unsuccessful person mean?)