Question

What is the best definition of a subordinate clause? a clause that has a subject a clause that depends on another clause to complete an idea  a clause that describes a noun a clause that expresses a complete idea by itself

Answer 1

I would say the answer here is "a clause that depends on another clause to complete an idea."

A subordinate clause cannot make sense on its own, so it needs to be attached to a main clause.

Example: I first met her in Paris where I lived as a small child. The bold text here is the subordinate clause.

..At least that's how I learned, lol. I hope this helps!