His reaction after masque dances? ‘Likely to feel sick (9)
I believe the answer is:
squeamish
''likely to feel sick' is the definition.
(I've seen this before)
'his reaction after masque dances?' is the wordplay.
'his reaction' becomes 'ish' (I can't explain this - if you can you should give a lot more credence to this answer).
'after' means one lot of letters go next to another.
'dances?' indicates an anagram (I've seen 'dance' mean this).
'masque' with letters rearranged gives 'squeam'.
'ish' put after 'squeam' is 'SQUEAMISH'.
Can you help me to learn more?
(Other definitions for squeamish that I've seen before include "Easily nauseated" , "Easily shocked by blood and gore" , "likely to feel sick" , "Delicate" , "Easily sickened or disgusted" .)