Persistent repetition of words or ideas is called

Perseveration is the uncontrolled repetition or continuation of a response (e.g., behavior, word, thought, activity, strategy, or emotion) in the absence of an ongoing occasion or rationale for that behavior or emotion (e.g., the topic or task requirements have changed). Perseverative behavior generally interferes with learning and adaptive behavior (e.g., effective interaction, on-task behavior, flexible shifting among topics and activities), and is believed to result from neurologic impairment.