An Adjective phrase is a set of words used to modify the noun or nouns in a sentence always containing an adjective acting as the head of the phrase, for example:
These flowers are gorgeous.
This car is absolutely perfect.
From all these sentences:
The big, brown dog sat next to the couch and chewed a bone.
YES
The dog sat next to the couch and chewed a bone loudly.
NO
The dog, Max, sat next to the couch and chewed a bone.
NO
The dog sat next to the couch and chewed a bone with her new puppies
NO
