Adjective

(head)

Supposed, or assumed to be.

*{{quote-magazine, date=2012-01

, author=Philip E. Mirowski , title=Harms to Health from the Pursuit of Profits , volume=100, issue=1, page=87 , magazine= citation , passage=In an era when political leaders promise deliverance from decline through America’s purported preeminence in scientific research, the news that science is in deep trouble in the United States has been as unwelcome as a diagnosis of leukemia following the loss of health insurance.}}

Normally assumed to be.

Said by some people to be real or true or to have happened, although this may not be so

Adjective

(en adjective)

Apparent, evident; meant for open display.

* 1956–1960 , (second edition, 1960), chapter ii: “Motives and Motivation”, page 32:

Motives, of course, may be mixed; but this only means that a man aims at a variety of goals by means of the same course of action. Similarly a man may have a strong motive or a weak one, an ulterior motive or an ostensible one.

* '>citation

In witch-trials the conflict was officially defined as between the accused and God, or between the accused and the Catholic (later Protestant) church, as God's earthly representative. [...]
Behind the ostensible conflict of the witch-trial lay the usual conflicts of social class, values, and human relationships.

Appearing as such; being such in appearance; professed, supposed (rather than demonstrably true or real).

The ostensible reason for his visit to New York was to see his mother, but the real reason was to get to the Yankees game the next day.