Subordinate clauses, also known as dependent clauses, are a type of clause that cannot stand alone as a sentence. They are dependent on an independent clause to form a complete sentence. Subordinate clauses are usually introduced by a subordinating conjunction such as 'BECAUSE, ' 'ALTHOUGH, ' or 'IF.' They provide additional information to the main clause and often contain a subject and a verb. The term 'elves' is a 5-letter solution for the crossword puzzle and is used to refer to a mythical creature in Germanic folklore.