* Noun: A state of great activity and energy, a lively and noisy crowd.
* Example: "There was a bustle in the marketplace as people shopped for the holidays."
* Verb: To move about in a busy way, to hurry or rush.
* Example: "She bustled around the kitchen, preparing dinner."
* Adjective: Characterized by great activity or energy.
* Example: "The city was a bustling hub of commerce."
Therefore, to know the exact part of speech, you need to look at the context in which the word is used.