Final answer:
The best antonym for rhapsodic is unenthusiastic.
Step-by-step explanation:
The best antonym for rhapsodic is unenthusiastic. Rhapsodic means to be highly enthusiastic and expressive, so the opposite would be lacking enthusiasm or being unenthusiastic. For example, if a person gives a rhapsodic retelling of a movie plot, they would be excited and enthusiastic about it. On the other hand, an unenthusiastic retelling would be the opposite, lacking excitement and enthusiasm.