As a writer, what does it mean to be "on word count?"

And as an editor, I find it a little precious when writers hit the word count precisely. It makes me wonder if they intentionally made a less than optimal choice in wording or phrasing in order to hit the number on the head. That said, I notice it, grimace and then forget about it. The piece is going to need editing regardless.

It doesn't matter what Minor Internet Celebrity meant by "on word count." It doesn't matter what the industry standard is. All that matters here is what your editor wants. So ask. It won't seem like you need your hand held; it'll seem like you want to do it right the first time, without needing hand-holding after.

In general, you have about 5% leeway under 2,500 words, and a bit more over that. But being spot on word count will win you the love of editors forever.

Maybe I take things literally, but if an editor told me to give him x words, I would hit x words, and not go over. He didn't ask for x words + wiggle room, but x words. My thinking here is that he says 1500, but really only wants 1200, maybe.

The only thing that comes to mind here is that you should not leave in copy for the editor to cut out (based on the reasoning that the editor is going to want to cut out stuff anyway). For freelance assignments, everything must fit, everything must be polished.

With the additional context you've given, I would cast "on word count" as a pithy shorthand for "follow editorial direction, and give them exactly what they have asked for." No editor will ever get annoyed if you ask for clarification on the word count. They may sound startled when you ask. Rest assured, that's "startled" in a good way. Trust me, editors have had a lifetime's worth of special snowflake blowhard precious Artists flaking off their flakiness all over the place. If you can be reliable, reasonable, and follow the instructions, they will love you forever.

Point well taken, 256. You're good.

I edit a reviews section of a magazine and when I give a word count that is the number of words I want. I know how many pages I've got, I know how many words fit on a page. If you go under, I've got dead space. If you go over, I've got no room so I need to spend time editing you down. I'll have lots of different pieces to edit at the same time so if I have to spend additional time just getting your piece to fit, I'll be a bit pissed off.

256 is spot on. Another thing you can do, if you have enough extra-but-interesting material, is offer a sidebar. Always ask first, though! If they don't take the sidebar, maybe it would make another article for another publication. Whenever I write a piece I see what's been cut and if I can flesh out that idea and sell it elsewhere. And read http://www.therenegadewriter.com/ -- they're great for boosting your writer-editor relationship skills.