An adverb phrase is simply a group of two or more words that function as an adverb in a sentence. Just as an adverb can modify a verb, adjective or another adverb, an adverb phrase of more than one word can further describe a verb, adverb, or adjective.
Examples:
Bob nodded like a bobblehead.
Meet me at the mall later this evening.
Without thinking, he turned down the road.
They must kiss before sunset to break the spell.
She went online for more information.
In the forest, many creatures snarl and growl.
I will not do that, never in a million years!
Dad spoke softly to calm her fears.
They have a house right by the ocean.
She slammed the door in a huff.
We will reconvene earlier than usual.