Tennyson
Few people would have considered the surname of this famous Victorian poet as a first name until Russell Crowe chose it for his son in 2006. But, as a rhythmic three-syllable patronymic, Tennyson has a lot going for it, not least of all the appealing nickname Tenny; it would make a novel choice for the son of a Dennis.
Other options: The poet's first name, Alfred, or the name of another esteemed bard, such as Eliot, Poe, Byron, Lowell or Lorca.

