1. A Project, person etc that enjoys only short lived success.
2. Something which disappoints by failing to deliver anything of value, despite a showy beginning
This originally had a literal meaning, i.e. a real flash in a real pan. Muskets used to have small pans to hold the gunpowder charge. An attempt to fire the musket in which the gunpowder flared up without firing a bullet would be called a 'flash in the pan'.
origin, The term is known since the late 17th century. Elkanah Settle, in Reflections on several of Mr. Dryden's plays 1687, had this to say:
"although the group had a number one hit, it was only a one hit wonder making them a flash in the pan."
"If Cannons were so well bred in his Metaphor as only to flash in the Pan, I dare lay an even wager that Mr. Dryden durst venture to Sea."
an identifying armband or badge. normally worn on the uppermost part of the arm and shoulder area to identify who or what you are.
when watching english 2nd world war films look out for the ARP's (Air Raid Precaution) during the London blitz. the abbreviation ARP is on the Brassard.