The phrase "an old black poodle" is a noun phrase. It describes a specific type of dog (a poodle) with particular characteristics (old and black). In this phrase:
- "old" functions as an adjective describing the age of the poodle.
- "black" functions as an adjective describing the color of the poodle.
- "poodle" is the noun, which is the main subject of the phrase.
Together, they form a descriptive phrase that conveys specific information about the dog.