Almost collapse before argument in shrill voice (8)
I believe the answer is:
falsetto
'shrill voice' is the definition.
'falsetto' can be an answer for 'voice' (falsetto is a kind of voice). I'm not certain of the 'shrill' bit.
'almost collapse before argument in' is the wordplay.
'almost' means to remove the last letter (most of the word but not all of it).
'collapse' becomes 'fall' (I've seen this in another clue).
'before' says to put letters next to each other.
'argument in' becomes 'setto' (I can't explain this - if you can you should believe this answer much more).
'fall' with its last letter taken away is 'fal'.
'fal'+'setto'='FALSETTO'
Can you help me to learn more?
(Other definitions for falsetto that I've seen before include "Unusually high voice" , "High-pitched male voice" , "Unnaturally high voice" , "Artificially high voice pitch" , "Strained sentiment" .)