zodiac22 Mar 2004
No. If the extra syllable is a two-syllable end-word, it works fine. For example, iambic pentameter is usually defined as ten syllables in an accented-unaccented scheme. But the best, most consistent pentameter writers (Pope comes to mind, and Shakespeare) often add an extra unaccented syllable on the end, as in the first line of Othello, "Tush! ne'er tell me; I take it much unkindly."
The real test will be to take it to an Irish pub, get smashed on pints of warm Guinness, and recite it very loudly. I can assure you it will work.