Odd thing for accountant to post with late tot
I believe the answer is:
nightcap
'late tot' is the definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.
'odd thing for accountant to post' is the wordplay.
'odd' indicates an anagram.
'for' means one lot of letters go next to another.
'accountant' becomes 'ca' (abbreviation for chartered accountant).
'to' means one lot of letters go next to another.
'post' becomes 'p' (this could be a standard abbreviation of which I'm unaware).
'thing' is an anagram of 'night'.
'night'+'ca'+'p'='NIGHTCAP'
'with' is the link.
Can you help me to learn more?
(Other definitions for nightcap that I've seen before include "Old headgear" , "Last drink of the day?" , "A drink before sleep" , "Tot, at bedtime" , "Last drink before bed" .)