Sort of sound was weirdly going round church (5)
I believe the answer is:
schwa
'sort of sound' is the definition.
(I know that schwa is a type of mid vowel)
'was weirdly going round church' is the wordplay.
'weirdly' is an anagram indicator.
'going round' is an insertion indicator (some letters go around others).
'church' becomes 'ch' (common abbreviation).
'was' anagrammed gives 'swa'.
'swa' placed around 'ch' is 'SCHWA'.
(Other definitions for schwa that I've seen before include "sound unstressed" , "Indistinct sound" , "Unstressed vowel (phonetics)" , "Stress-free sound" , "Uh' sound" .)