Are there any medals for a bicenquinquagenary celebration? How many years does that mouthful of a word represent?

Decoding 'bicenquinquagenary' is easy. Two hundred years can be either "bicentennial" or "bicentenary." Break apart either one and insert in the middle the decade and the year:

Thus 'BICENQUINQUAGENARY becomes 'BICEN - QUIN - QUAG - ENARY.

BICEN - 200 years.

QUIN - 40 years.

QUAG - 5 years.

ENARY - anniversary.

I'd like to know how "quin" gets to 40 and "quag" gets to 5. You call the answer "precise", by which I guess you mean detailed, but the question is whether it's correct.

You can check http://arts.cuhk.edu.hk/Lexis/Latin/ to see that "quinquaginta" is Latin for 50, and the "g" is part of the suffix for ten-fold, as in words like octogenarian or Septuagint.

I see a delightful debate in the making here. And it is not often that I ever disagree with Dick Johnson; let alone with any confidence. To support my contention that bicenquinquagenary refers to the 250th anniversary, I offer the following Wikipedia definition: "Semiquincentennial - 250 years. Variation: Bicenquinquagenary was used by Princeton University in 1996, and by Washington and Lee University in 1999."

The word is also specifically defined in the Gustavus Adolphus College Style Guide, from which I excerpted the above image. Also, the Latin word for "fiftieth" is "quinquagesima." And the day a "quin" of anything refers to four instead of five is the day my dog becomes a quinaped.