Ostensible is an adjective that means stated or appearing to be true, but not necessarily so. 

Having been around since the mid-18th century, our word of the is derived from the Latin word ostentere (oh sten TEAR ay) which means ‘to display.’ Here’s an example:

The ostensible reason for not giving the employees free coffee anymore was that the company could no longer afford it. But looking at the money the company spends on decorating the hallways makes it hard to believe that.