Merriam-Webster's Word of the Day for May 05, 2012 is:
putative • \PYOO-tuh-tiv\ • adjective
1 : commonly accepted or supposed 2 : assumed to exist or to have existed

Examples:
Corporate restructuring and a need to cut costs were the putative reasons for the layoffs.

"The phrase 'wacky woman' was being tossed about frequently in descriptions of Maryland's putative lottery winner…." — From an article by Susan Reimer in the Baltimore Sun, April 4, 2012

Did you know?
There's no need to make assumptions about the root behind "putative"; scholars are quite certain the word comes from Latin "putatus," the past participle of the verb "putare," which means "to consider" or "to think." "Putative" has been part of English since the 15th century, and it often shows up in legal contexts. For instance, a "putative marriage" is one that is believed to be legal by at least one of the parties involved. When that trusting person finds out that his or her marriage is not sanctioned by law, other "putare" derivatives, such as "dispute," "disreputable," "reputed," "imputation," and "deputy," may come into play.