Stare at end of spectacle – then you shout audibly (7)
I believe the answer is:
eyeball
'stare at' is the definition.
(to eyeball something is to stare at it)
'end of spectacle then you shout audibly' is the wordplay.
'end of' indicates one should take the final letters.
'then' means one lot of letters go next to another.
'you' becomes 'ye' (historical version of 'you').
'shout audibly' becomes 'ball' (I can't explain this - if you can you should believe this answer much more).
The last letter of 'spectacle' is 'e'.
'e'+'ye'+'ball'='EYEBALL'
Can you help me to learn more?
(Other definitions for eyeball that I've seen before include "Observe closely" , "making us stare" , "Stare at closely (colloq.)" , "" - to - " = in close confrontation" , "Label ye (anag)" .)