Either way, you have been warned, so let the groans commence.
Let's start at the beginning, with the icon.
1. a painting of Jesus Christ or another holy figure, typically in a traditional style on wood, venerated and used as an aid to devotion in the Byzantine and other Eastern Churches.
synonyms: image, idol, portrait, likeness, representation, symbol, figure, statue, model
"an icon of the Madonna hangs on the wall"
2. a person or thing regarded as a representative symbol or as worthy of veneration.
"this iron-jawed icon of American manhood"
Defining "iconic" and summarizing my annoyance:
The original meaning of iconic was essentially "resembling an icon", but today it more often seems to mean "so admired that it could be the subject of an icon". And with that meaning, iconic has become part of the language of advertising and publicity; today companies and magazines and TV hosts are constantly encouraging us to think of some consumer item or pop star or show as first-rate or immortal or flawless—absolutely "iconic" — when he or she or it is actually nothing of the kind.
On Facebook, a friend wrote: "Pilsner Urquell and Guinness are iconic. Fight me."
No way I'm fighting. Both these examples of usage are correct, as they're well-established and noted for excellence. In fact, they're venerable -- and I venerate them.
However, just the other day the local chain newspaper used the word "iconic" to describe the proposed new park in Clarksville. But this park does not yet exist; therefore, it cannot be iconic.
Then one of Team Gahan's taxpayer-compensated propagandists referred to Rally's/Checkers as "iconic." I almost threw up. While this cookie-cutter atrocity is well-established, it is NOT noted for its excellence -- in terms of iconic, it is nothing of the kind.
Ironic? That's more like it. Let's summarize. This historic photograph is iconic -- after all, Wikipedia says so.
This crappy fast food joint isn't.