What is cold iron

[caelic]

Actually, technically speaking, those should both be pronounced "fohrt."  It comes from Middle French.  The prevalence of the "fohr-tay" pronunciation is likely due to confusion as a false cognate with the musical term "forte," meaning "loudly" or "strong," which comes from Italian.

Yep.  Of course, usage determines propriety in the long run, and therefore, most dictionaries today acknowledge "for-tay" as a valid pronunciation, just as they generally regard "octopi" as a valid plural of "octopus" right alongside "octopuses." (Though, if we really want to be technical, it should probably be "octopodes.")

[awaken_D_M_golem]

iirc - 1e cold iron, is another variant on the: silver weapons  vs. Lycanths.
DR 5/cold iron is a downstream version.

Lots of things don't.  For instance, the English word "forte" is properly pronounced "fort," not "for-tay."  (Usage determines propriety, of course, so "for-tay" is becoming acceptable.)

Doesn't seem right, does it?

Proper English is a bitch.

... which is pronounced be-yotch in "proper" society.