Some verbiloquent folk use this word as if to mean the same as "ultimate". Of course it doesn't mean that; it means "next to the last" (in a series).  ''Antepenultimate'' means the "the one before the penultimate one" (or "next-to-the-next-to-the-last".

In the same way that ''peninsula'' is almost an island, ''penultimate'' is almost the last.

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In other words, "penultimate" means "second best."  

Nope.  "Ultimate" does not mean "best", marketing weenie speak notwithstanding.  In certain contexts, it is used this way; however, it is not the primary meaning.

''The basis for the impression of "ultimate" meaning "best" is because you usually stop looking for something once you think you've found the best one.  Hence the best one you found was the '''last''' one you looked at -- the ultimate one.  But the word "ultimate" itself does not literally mean "best".  At least that's what I think :)''

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Example:  The penultimate syllable receives the stress in the word "redaction."

Example:  "Welcome to the Pit of Penultimate Darkness!  Apparently someone has opened a pit slightly darker than ours."
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And ''preantepenultimate'' means three from the last!