Mapmakers following city descent (6)
I believe the answer is:
bathos
'descent' is the definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
'mapmakers following city' is the wordplay.
'mapmakers' becomes 'OS' (Ordnance Survey).
'following' means one lot of letters go next to another.
'city' becomes 'bath' (English city).
'os' put after 'bath' is 'BATHOS'.
Can you help me to learn more?
(Other definitions for bathos that I've seen before include "let-down" , "Anticlimax, descent from important to trivial" , "Ludicrous anticlimax" , "Unintentional lowering of tone" , "Unintentional slip from serious to trivial mood" .)