For a heavenly body's space visitant, it's late in the day (6)
I believe the answer is:
sunset
'day' is the definition.
The definition and answer can be both related to time as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'for a heavenly body's space visitant it's late in the' is the wordplay.
I cannot really understand how this works, but
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is present in the answer.
'it' could be 'e' ('e' can mean 'electronic' which is similar to 'IT') and 'e' is present in the answer.
'heavenly body's' could be 'suns' (Sun is an example) and 'suns' is found in the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for sunset that I've seen before include "Evening glow" , "End of the day, getting dark" , "star not in the ascendant at this time" , "After which day becomes night" , "Final declining phase (of something)" .)