Yes, any coin that doesn't have the same dimensions as the real coin is a replica.
The value of 1889 Morgan silver dollar replica ranges from $23.01 to $26.76
All replica coins sold in the USA are required to be marked with the word "COPY" in a conspicuous location on the coin. If a replica does not have the word "COPY", then it is a counterfeit.
If you think it's an older replica made before 1973 and does not have "copy" on it, take it to a coin dealer.
The only value is if there is silver in it, if not no collection value at all.
This stuff has no numismatic collectible value. As for the value, try eBay. For some reason they do sell a lot of Morgan dollar copy's.
Morgan dollars were minted from 1878 to 1904 and in 1921. Please check again. You may have a replica or novelty piece.
All Morgan dollars have the same reverse design, with only a few very minor variations. None were minted without the words ONE DOLLAR. It's possible you have a copy, replica, or counterfeit but it would have to be examined in person to know for sure.
A Morgan dollar IS a silver dollar. The term Morgan refers to the designer George T. Morgan who created the images used from 1878 to 1904 and in 1921.
Without examining the coin it is impossible to tell if it is genuine or not. But there are legitimate 1921-S (Morgan) dollar coins struck. If you have a Morgan dollar that has the same weight, dimensions and design as known legitimate coins (and the coin doesn't say COPY or REPLICA or anything like that on it), it is most likely genuine. 1921 is an incredibly common date for Morgan Dollars and most counterfeiters won't bother making deceptive counterfeits of it.
Any "Morgan dollar" that's 5 inches in diameter isn't real. You have some kind of copy, replica, or maybe even a privately-made bullion piece. Unless it indicates that it's made of silver (e.g. it says something like ".999 fine" on it somewhere) you'd need to have it examined in person to know what it is. And without an indication that it's made of silver, it's likely to be a base-metal replica.
Below is a picture of a Morgan dollar coin.
A rare Morgan Silver Dollar is 1876.