Enthusiasts may wax it (7)
I believe the answer is:
lyrical
I'm afraid I can't explain this answer.
Can you help me to learn more?
(Other definitions for lyrical that I've seen before include "Expressing deep emotion" , "Enthusiastic - expressing the writer's feelings" , "We may wax this" , "In poetic words, song-like" , "Highly enthusiastic" .)