I have 1 1/2 PVC tubular and a female threaded ABS sticking out of the wall under a kitchen sink..

The 1 1/2 tubular slides in loose into the ABS because of the differences in OD (tubular) versus ID ABS so a Slip nut connection would not work properly.

I see under another kichen sink that they may have just glued in the tubular to the ABS with a massive amound of glue to make it work?

Alternativley I could just go with ABS right up to the Garbage disposal discharge ?

Another idea I was thinking of was threading a short section of ABS until the threaded section of the ABS to make it suitable to hook the tubular up to the ABS using a Fernco coupler.

Any suggestions?

A slip joint nut/gasket is made specifically to join tubular to IP size.

Ok, I think I made several mistakes in stating this problem.

Now I think it is 2 inch ABS male Thread coming out of the wall and it needs to hook up to a garbage disposal outlet ( presumably 1 1/2 inch tubular) (through a p-trap).

So I'm thinking now that I will have to get a piece of 2 inch ABS pipe and a 2 to 1 1/2inch abs hub reducer?

If there's enough 2" sticking out from the wall, cut off the threaded adapter and then glue on a 2x1½ reducer, with an 1½" trap adapter glued to the reducer. If you don't have enough pipe stubbed out, screw a 2" female adapter on and then 2x1½ bushing and then an 1½" trap adapter.