Monometer

In poetry, a monometer is a line of verse with just one metrical foot, exemplified by this portion of Robert Herrick's "Upon His Departure Hence":

Thus I
Passe by,
And die:
As one,
Unknown,
And gone.

A more famous example is the slogan of the Milk Marketing Board in the 1970s:

Drinka
Pinta
Milka
Day

whose trochaic monometer echoes Hiawatha to assert the primitive importance of milk. A poem with lines of absolutely minimal metrical length is:

Beanz
Meanz
Heinz