If you are recently Terminated, would it be better to be honest and tell this to the interviewer or much better to keep this information from them.?

Yes it is excellent to be fair...............................

It is much better not to tell the interviewer that you are recently terminated in order to avoid the interview develop more scepticism about you.

General rule during interview is to be HONEST well at least in my opinion, why because lying will not bring any good to anyone looking for job. Eventually the company will find it out ( lying ) and that is ground for anotther termination.   

It depends. Okay to tell him if terminated reason is reasonable like lay-off, demobilization, project shutdown. Even we can tell him if the reason purely a personal bias.