Thanks.  That is very interesting.  At the M-W free website (e.g.),
here is what I got for "plebian":

 The word you've entered isn't in the dictionary. Click on a
 spelling suggestion below or try again using the search box
 to the right.

 Suggestions for plebian:
    1. plebeian
    2. Polabian
    3. pole bean
    4. plebeians
    5. Playbill
    6. pliable
    7. Pelion
    8. Polabians
    9. plebeianly
    10. play by ear

As I mentioned, _I_ could not find "any" on-line reference for
"plebian".  I suppose I should have limited that assertion to _free
websites_.  I wonder if the Unabridged calls "Febuary" a variant of
"February"?  

Of course, "theatre" is a common variant spelling of "theater".  I am
not up on my dictionary nomenclature, but "plebian" seems to be rather
far afield to be a mere "variant".  That being said, I just dug out my
5" thick Webster's Dictionary of the English Language and the listing
is tamely "plebeian, plebian", so I sit corrected.  

BTW, I could not find a reference to the dictionary that MS Office
2000 uses.  Under "About", it just says that the "spelling correction
system" is by Lernout & Hauspie.

Again, Bob, thanks.  - Igor