adjective
: having the capacity to subordinate or the function of subordinating ; usually : introducing a subordinate clause : joining a subordinate to a main clause
if in “I will come if I can” and until in “they fished until it was dark” are subordinating conjunctions
• sub·or·di·nat·ing·ly ̷ ̷ˈ ̷ ̷ ̷ ̷ˌ ̷ ̷ ̷ ̷ ̷ ̷, ̷ ̷ˌ ̷ ̷ ̷ ̷ˈ ̷ ̷ ̷ ̷ ̷ ̷ adverb