Daughter in a hole before Xmas (6)
I believe the answer is:
advent
'xmas' is the definition.
The definition and answer can be both related to time as well as being singular nouns.
Maybe there's an association between them I don't understand?
'daughter in a hole before' is the wordplay.
'daughter' becomes 'd' (genealogical abbreviation).
'in' is an insertion indicator.
'hole before' becomes 'vent' (vent is a kind of hole. I am not sure about the 'before' bit.).
'a'+'vent'='avent'
'd' placed into 'avent' is 'ADVENT'.
Can you help me to learn more?
(Other definitions for advent that I've seen before include "when the Church year begins" , "observed by Christian church" , "Christian season" , "Coming, arrival" , "Forty days preceding Christmas" .)