Hendecasyllabic
/ˌhendekəsɪˈlæbɪk/
Definition 1 of 1
Pro Tip 1/3Poetic Rhythm
Understanding hendecasyllabic helps grasp the flow and beat in poetry. 
Her favorite sonnet was written in a smooth hendecasyllabic rhythm.
Pro Tip 2/3Italian Origin
The term is often associated with Italian poetry, where it's prominent. 
Dante frequently used hendecasyllabic lines in 'The Divine Comedy'.
Pro Tip 3/3Not Commonly Used
Hendecasyllabic is a specific term not often seen outside literary contexts. 
I was surprised to find hendecasyllabic lines in a modern pop song's lyrics.