Unfading, your old dogs flushed cat from yacht, maybe (11)
I believe the answer is:
amaranthine
'unfading' is the definition.
(synonyms)
'your old dogs flushed cat from yacht maybe' is the wordplay.
I cannot quite see how this works, but
'your' could be 'thine' (I've seen this before) and 'thine' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for amaranthine that I've seen before include "never fading" , "Ever-fresh" , "Like a plant" , "Flowery" .)