By Webster’s definition, Iconic means ‘of, relating to, or having the characteristics of an icon’, which in essence reminds me of looking for the Wizard’s 1E D&D Protection from Evil spell only to be told to ‘see Cleric spell of the same name’, unless, of course, you know the word Icon means ‘a person who is very successful and admired’.
Now, having established the meaning, I intend to look at the evolution of ‘Iconic Characters’ [thus Iconic Character Classes] in the RPG setting.
It can be universally accepted that Paizo coined the phrase ‘Iconics’ with the release of its Pathfinder Adventure Paths [and their beta versions from Paizo’s Dungeon Magazine], but that is simple semantics. In reality, the first true ‘Iconics’ were from the Wizard of the Coast release of D&D 3rd Edition, namely Krusk, Jozan Vadania, Tordek, etc.
These characters were really the first to take players through the game by repeating their exploits in both artwork and description. Created by artists Todd Lockwood and Sam Wood, players from a whole new D20 generation were introduced to this new system and cut their teeth with the WotC Iconics.
However, I would contend that perhaps the definition of Iconic doesn’t have to depend on players of RPGs actually knowing the character’s name, but rather recognizing their image. If that is the case, then the role of character class Iconics goes back much further.