Wonders if anemone's held back by level of acidity (9)
I believe the answer is:
phenomena
'wonders' is the definition.
(I've seen this before)
'anemone's held back by level of acidity' is the wordplay.
'held back' shows that the letters should be reversed in order.
'by' is a charade indicator (letters next to each other).
'level of acidity' becomes 'ph' (I can't explain this - if you can you should believe this answer much more).
'anemone' in reverse letter order is 'enomena'.
'enomena' put after 'ph' is 'PHENOMENA'.
'if' is the link.
Can you help me to learn more?
(Other definitions for phenomena that I've seen before include "He-man open to remarkable things or wonders" , "Remarkable events or things, wonders (9)" , "Events that may be observed" , "strange doings!" , "Happenings" .)