I know there is a word out there for this, but I can't remember it. The definition is using a specific place name to refer to a general community or group. For example, we say Washington to refer to the federal government, or Wall Street to reference the financial industry, or we say Hollywood when we mean the entertainment business in general.

I've tried searching for it, but I'm failing miserably at coming up with the answer. Can anyone help?

Welcome, Koltrane

synecdoche
[L. a. Gk synekdoche] /suh NEK duh kee/ (rhymes with Schenectady : )
a figure by which a more comprehensive term is used for a less comprehensive or vice versa; as whole for part or part for whole, genus for species or species for genus, etc. (compare metonymy)

metonymy
/met ON ah me/ a figure of speech in which one word or phrase is substituted for another with which it is closely associated, as in the use of Washington for the United States government or of the sword for military power

source: worthless word for the day : )

synecdoche ... as whole for part or part for whole

aka totum pro parte and pars pro toto by those who like our tongues Latinate.

Thank you thank you thank you! Metonymy is the word I was seeking (and have been for some time). You people are great!

Synecdoche fits my feeble wording of what I was seeking, but that is really more like calling your car your wheels. It is close, but metonymy (or more specifically, metonym) is the EXACT word.

Again, a million thanks. That itch is finally scratched!

Welcome, and stick around - you owe us a backscratch.