A sentence that contains an incomplete thought is known as a:

A sentence containing an incomplete thought is known as a fragmented sentence. A fragmented sentence fails to express a complete idea because it is missing either a subject or a verb, or it may not provide enough information to stand alone as a complete thought. For instance, phrases that start with subordinating conjunctions or dependent clauses often leave the reader waiting for additional information to clarify the thought.

In contrast, terms like 'confused sentence' or 'partial sentence' are not standard terms used to describe sentences in language. A run-on sentence refers to a grammatically incorrect structure where two or more independent clauses are joined without appropriate punctuation or conjunctions. Understanding these distinctions is crucial for recognizing and correcting different types of sentence errors in writing.