Where circus audience is engrossed (6)
I believe the answer is:
intent
'is engrossed' is the definition.
(synonyms)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for intent that I've seen before include "Firm - plan - steadfast - purpose" , "Design, aim" , "Eager" , "'Purpose, aim (6)'" , "Mean to" .)