Open to doubt or challenge; problematic.(adjective)
Not yet determined or specified.(adjective)
Of dubious morality or respectability: a questionable reputation. (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.