Viewer sunk half an inch into the drink (7)
I believe the answer is:
watcher
'viewer' is the definition.
(I know that viewer can be written as watcher)
'half an inch into the drink' is the wordplay.
'half' means to take half the letters.
'into' means one lot of letters goes inside another.
'the drink' becomes 'water' (I've seen this in another clue).
'inch' with half the letters taken is 'ch'.
'ch' put into 'water' is 'WATCHER'.
'sunk' is the link.
I am not very happy about this link. It may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for watcher that I've seen before include "Onlooker" , "Big Brother?" , "I observe" , "Alert observer" , "One who observes" .)