I am not sure what you are asking about.
Masonite is the name of a corporation. CURRENTLY they make doors.
Masonite originally developed a wood composite material generically called Hardboard.
There are a number of different hardboard materials. Siding is one. Tempered hardboard is another. That is commonly used for peg boards although it is available without the holes.
And as is common the original product it calls by the company name and vice versa.
But Masonite went on to develope a number of materials. It is possible that at one time they sold an adhesive under that name.
But if you are talking about using hardboard as a substrate to mount tile on don't.
If you are talking about an adhesive don't.
For a shower use thinset over any approved substrate. That can be of the tile backer boards. Or can be be one of the applied systems such as Kerdi.