Fear induced by gnats swarming (5)

I believe the answer is:

angst

I'm a little stuck... Click here to teach me more about this clue!

'fear' is the definition.
(thesaurus)

'induced by gnats swarming' is the wordplay.
'gnats' can be anagrammed to 'ANGST'.
Though, I'm not clear how the anagram is indicated.

Can you help me to learn more?

(Other definitions for angst that I've seen before include "Gnats (anag.)" , "feeling worried?" , "Painful feeling" , "Strong feeling of anxiety/dread" , "Terrible butterflies" .)

I've seen this clue in The Globe and Mail.

Want a hint initially instead of a full solution? Install my app