In poetry, a tetrameter is a line of four metrical feet. However, the particular foot can vary, as follows:

• Anapestic tetrameter:
  • "And the sheen of their spears was like stars on the sea" (Lord Byron, "The Destruction of Sennacherib")
  • "Twas the night before Christmas when all through the house" ("A Visit from St. Nicholas")
• Iambic tetrameter:
  • "Because I could not stop for Death" (Emily Dickinson, eponymous lyric)
• Trochaic tetrameter:
  • "Peter, Peter, pumpkin-eater" (English nursery rhyme)
• Dactylic tetrameter:
  • Picture your self in a boat on a river with [...] (The Beatles, "Lucy in the Sky with Diamonds")
• Spondaic tetrameter:
  • Long sounds move slow
• Pyrrhic tetrameter (with spondees ["white breast" and "dim sea"]):
  • And the white breast of the dim sea
• Amphibracic tetrameter:
  • And, speaking of birds, there's the Russian Palooski, / Whose headski is redski and belly is blueski. (Dr. Seuss)