Rare quality such as Baths spoken of (8)
I believe the answer is:
sparsity
'spoken of' is the definition.
The definition suggests a singular noun which matches the answer.
'rare quality such as baths' is the wordplay.
I cannot quite see how this works, but
'rare' could be 'r' (listed by Oxford Dictionary of Abbreviations) and 'r' is present in the answer.
'as' is found in the answer.
'quality' could be 'pity' (pity is a kind of quality) and 'pity' is present in the leftover letters.
A single letter 's' remains which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for sparsity that I've seen before include "Scantiness" , "Thinly scattered state" , "Thinly-scattered state" , "Low density" , "Shortness of supply" .)