Not adhering to convention; out of the ordinary.(adjective)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "unconventional" in a sentence
"The term unconventional resources is applied to a broad category of fuels like shale gas, tar sands and other forms of oil and gas that require sophisticated technology to extract and are typically more expensive to develop."
"He chalks up some of the perhaps unwanted attention he gets in the press to what he describes as his unconventional style of leadership."
"The Zen Attraction system, while highly unconventional, is 100% ethical and does not involve any kind trickery or hypnosis."