It's built to keep a flower in its bed (10)
I believe the answer is:
embankment
'bed' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'it's built to keep a flower in its' is the wordplay.
I cannot quite see how this works, but
'a' could be 'an' and 'an' is located in the answer.
'it' could be 't' (abbreviation. e.g. in 'tis) and 't' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for embankment that I've seen before include "Riverside wall" , "Mound" , "protection against rising liquidity" , "rampart" , "Wall built to prevent flooding" .)