Final answer:
The antonym of 'enthralling' is 'tedious.'
Step-by-step explanation:
The antonym of 'enthralling' is 'tedious.' While 'enthralling' means captivating or fascinating, 'tedious' means boring or monotonous.
For example, if a book or movie is enthralling, it means it is very interesting and holds your attention. On the other hand, if something is tedious, it means it is dull and tiresome.