Dictionary.com
Thesaurus.com

subordinating conjunction

American  
Or subordinate conjunction

noun

Grammar.
  1. a conjunction introducing a subordinate clause, as when in They were glad when I finished.


subordinating conjunction British  

noun

  1. a conjunction that introduces subordinate clauses, such as if, because, although, and until Compare coordinating conjunction

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of subordinating conjunction

First recorded in 1870–75; subordinate + -ing 2

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

The butler can be a “pain in the glute” and a “blabber,” Carter tells us, while Mr. Bowles-Fitzpatrick gently chides that you should never “begin your sentence with a subordinating conjunction,” like “because.”

From New York Times

For that matter, many of the words that were traditionally called subordinating conjunctions, like before and after, are actually prepositions.

From Literature

While or any other subordinating conjunction introduces a dependent clause; a dependent clause is not a sentence; it can never stand alone.

From Project Gutenberg