Irregardless means the same as regardless: without being changed or pushed around by something. You will hear it in speech, and you will see it in loose writing. Many teachers, editors, and exam markers treat it as a mistake. The reason is that regardless already means “without regard,” so the extra ir- (not) looks like a second “not” that does not add a new meaning. Dictionaries still list it, usually with a note that some people dislike it. Though actually, people who say irregardless are not trying to be clever; the word probably grew as a mix of irrespective and regardless, and the meaning is perfectly clear. For school English, tests, and careful writing, use regardless or irrespective of. Save irregardless for when you are showing how someone talked.

不管怎樣、無論（很多人認為不標準；正式寫作用 regardless）