The stress mark of the word abbreviation?

The word "abbreviation" has two stress marks, depending on whether it's used as a noun or a verb:

* Noun: ab·bre·vi·a·tion (stress on the first and fourth syllables)

* Verb: ab·bre·vi·ate (stress on the first and third syllables)

This is because the stress shifts to the penultimate syllable when it's used as a verb.