In which to spend the rest of your life (3)
I believe the answer is:
bed
'in which to spend the rest of your life' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how they can define each other.
This is the entire clue.
Can you help me to learn more?
(Other definitions for bed that I've seen before include "In which to place the body of flowers" , "(Garden) plot" , "One with flower, sleeper, in" , "might be laid here" , "pit" .)