The phrase "teeter totter" is a trochaic dimeter.
Step-by-step explanation:
A trochee (adj. "trochaic") is a metrical foot made of a stressed syllable followed by an unstressed syllable. Here, the uppercase syllables are stressed, the lowercase is unstressed.
TEE ter / TOT ter
Now we count how many feet (trochees) are in the phrase. Teeter totter has two feet, making it a dimeter.