Here are some possibilities:
* Huckle-buckle: This refers to the sound of something moving quickly or with a bumpy motion. It could be used to describe a cart going over rough terrain, a person walking quickly, or even the sound of a heart beating rapidly.
* Huckle-berry: This refers to a type of berry, typically black or blue, that grows in clusters on shrubs.
* Huckleberry Finn: This is a character in a famous novel by Mark Twain. The term "huckleberry" itself can be used as a slang term for a mischievous or adventurous person.
Can you give me more context about where you heard "huckle huckle"? That would help me understand what it might mean.