Better practice would have been to cite your source. Believe it or not, different dictionaries give different definitions for words. This does not sound like you are claiming credit for someone else's work (what I normally thikk of as plagiarism) but rather being a bit sloppy. There is a difference to me.
However, plagiarism.org, has a definition that includes quoting something without citation.
When you say the teacher accused you of plagiarism, what, exactly, was said and done? Did you get a failing mark on a project or reported to the principal? Were you threatened with suspension or some other sort of discipline?
Talk about this with your parents and counselor. See whether it can be straightened out. Unless this make a difference in your ability to go to school, I can't see involving a lawyer.
Confidential information should not be disclosed in this Internet forum. This answer is not legal advice, which requires a personal connection and far more facts. This attorney does not give legal advice over the Internet. This is a general statement about law, not advice.
Your school has an administrative appeal process for resolving these kinds of disputes. It is set forth in your student handbook, on the school's web-site and in your enrollment/admission materials. You must pursue this process, including timely satisfaction of all steps, before you have any right to bring any legal claim.
You have a right to utilize legal counsel in the admin appeal process and if the school is proposing serious discipline, you should have an attorney. Plagiarism is considered an "integrity violation" by all colleges and universities and discipline on that ground can keep you out of grad and professional school, professional internships, and other post-graduate educational programs. It can affect your eligibility for military service, state licensing, and of course post-grad employment.
If the evidence is weak, you may be able to defeat the allegation in the appeal proceeding. If the evidence is strong, an attorney can sometimes negotiate a "safe" resolution that accomplishes the school's purpose while keeping the matter confidential and allowing the student to go forward without a disciplinary record that limits so many future opportunities.
My responses to questions on Avvo are never intended as legal advice and must not be relied upon as legal advice. I give legal advice only in the course of an attorney-client relationship. Exchange of information through Avvo's Questions forum does not establish an attorney-client relationship with me. That relationship is established only by individual consultation and execution of a written agreement for legal services.
I agree with the fine answers of my esteemed colleagues, I trust you will heed their wise words.
Disclaimer Information on this site is provided by Brian Scott Wayson as general information, not legal advice, and use of this information does not establish an attorney-client relationship. If you have questions about your specific situation, please call an attorney.