A mare's nest, so to speak? (6)
I believe the answer is:
stable
This clue might be a double definition.
'a mare's nest' is the first definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Perhaps there's an association between them I don't understand?
'to speak?' is the second definition.
Although both the answer and definition are verbs in their base form, I cannot understand how they can define each other.
'so' is the link.
Can you help me to learn more?
(Other definitions for stable that I've seen before include "Firmly-fixed; building" , "Firm - building for animals" , "Horse barn" , "Not wobbly" , "Solid" .)