Pass out with utmost enthusiasm (5)
I believe the answer is:
swoon
This might be a double definition.
'pass out' is the first definition.
(swooning is a kind of passing out)
'utmost enthusiasm' is the second definition.
Although both the answer and definition are singular nouns, I cannot see how one could define the other.
'with' acts as a link.
Can you help me to learn more?
(Other definitions for swoon that I've seen before include "Show ecstasy" , "Display of extreme emotion" , "experience ecstasy" , "Faint (with emotion)" , "Fall fainting" .)