Informal Doubtful; uncertain: an iffy proposition. (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 "iffy" in a sentence
"Under the Bush administration, instead of building a framework that would embrace broader strategies, we invested, for instance, billions of dollars in iffy research to abate GHG emissions primarily from oil refineries and power plants, by pumping it into the subterranean geological strata."
"I dunno, I see "Syfy" and I see "siffy" at best ... and "iffy" is how I'm classifying this plan, in the end."
"One thing about the Friday the 13th remake/reboot/whatever you may call it that makes me a bit iffy is that they are redoing one of the two most iconic horror franchises (the other being Nightmare on Elm St) from when I was growing up."