Wiktionary
n. (context grammar English) A sentence that contains one independent clause and no dependent clause.
WordNet
n. a sentence having no coordinate clauses or subordinate clauses
Usage examples of "simple sentence".
That simple sentence spawned a sudden silence in which a falling pin would have sounded like an anvil, and he nodded much more seriously.
Languages are species-specific, but this thing managed to make sense and even construct a simple sentence that meant something.
But slowly the distinctions between the sounds he could hear became plainer, and he was able to grasp in a dim way the meaning of a few words out of each simple sentence before the code form was spelled out.
I said, my stomach tightening another notch at the danger present in that simple sentence.
His awkwardness had prevented him from uttering as much as a simple sentence.