Scottish river visible around posh quarter (6)
I believe the answer is:
fourth
'quarter' is the definition.
(a quarter is a fourth of something)
'scottish river visible around posh' is the wordplay.
I cannot quite see how this works, but
'river' could be 'r' (abbreviation) and 'r' is found in the answer.
'around' could be 'o' (a round letter) and 'o' is found in the answer.
'posh' could be 'u' (abbreviation for upper-class - opposite to non-U) and 'u' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for fourth that I've seen before include "Almost winning medal?" , "Journalism is called the . . . . . . estate" , "(and 4) The press" , "not among the medal winners?" , "Date in July celebrating American independence" .)