A thin layer of material surrounded astronaut's home by the second day of the week (6)
I believe the answer is:
tissue
'week' is the definition.
Although both the answer and definition are singular nouns, I can't understand how they can define each other.
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for tissue that I've seen before include "Bodily matter" , "light material" , "See 17" , "Thin soft disposable paper" , "Thin fabric" .)