The definition of a writer is someone who writes. Period. There are no other requirements. There are no other add-ons which will somehow make you a "real" writer. A writer is not defined by whether he is paid for his writing or not. Neither is a writer based on whether she's received accolades or awards. A writer does not need a nod, smile, or any form of acknowledgement, from anyone, in order to be defined as a writer. A writer isn't even dependent on having readers, as nice as that can be.
A writer is not one who attends events to speak about writing. A writer is not someone who talks about his great idea for a novel that he'll never start. A writer is not someone who has studied the technical craft and history of writing. A writer is not one who reads (or even adores) stories.
Of course, all of these things can help a writer. It's certainly nice to be acknowledged, and it's incredibly rewarding to get a paycheck through your pen. Awards are wonderful, and excellent writers may often be asked to speak at various events about their work. But none of this makes a writer.
Whether or not you are a true writer, my friend, is completely up to you. This fact can be both encouraging and unsettling. It is at once the most simple, and the most difficult, formula to follow.
Writers write.
If you have never written before because it seemed out of your reach, you're wrong. Writing is not some exclusive club reserved for the intellectual and/or creative elite. No matter your career, no matter your experience, no matter your skill level, if you have a desire to write, the only thing holding you back is you. Sure, it will take practice to develop your abilities--but writing is one of the very few things you can begin without any costs, any training, any equipment. Start now; if you have the inkling inside you, don't wait! Don't let some stupid voice behind your shoulder whisper you can't, or you're not good enough, or you'll never be published. Don't listen to that bullshit. Everyone is good enough to get started. Start writing, and then remind yourself: You're a writer. You know how I can tell?
Because writers write.