Final answer:
The phrase 'Since I ate dinner' is an example of a dependent clause.
Step-by-step explanation:
The phrase 'Since I ate dinner' is an example of a dependent clause. A dependent clause is a group of words that contains a subject and a verb but relies on an independent clause to complete its meaning. In this case, 'Since I ate dinner' cannot stand alone as a sentence and needs an independent clause to provide the full meaning.