Longman Dictionary of Contemporary English
Wiktionary
n. (context grammar English) A clause that cannot stand alone as a sentence, but functions as either a noun, adjective or adverb in a sentence.
WordNet
n. a clause in a complex sentence that cannot stand alone as a complete sentence and that functions within the sentence as a noun or adjective or adverb [syn: dependent clause]
Usage examples of "subordinate clause".
Widow Amsel nodded after every subordinate clause uttered by the fluent principal.
What he intended by this austere collection of four words was if you fed us better food, I work a great deal harder, but to voice a subordinate clause beginning with if was quite beyond his capacity, and comparisons like harder and better were refinements of thought he could not master.
Towards the end, such is the indirection on display, Miss Didion seems incapable of starting a new subordinate clause without splintering off into a new paragraph.