Unit of Poetic Rhythm; Anagram of Pens Ode
Puzzle 19 of City Nicknames Hard Pack
Question is: Unit of Poetic Rhythm; Anagram of Pens Ode
and the answer is: SPONDEE
Word Meaning:
SPONDEE — (poetry) A word or metrical foot of two syllables, either both long or both stressed.
Definitions from Wiktionary.