Doctor, calculating type, around one part of year (9)
I believe the answer is:
midsummer
'year' 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?
'doctor calculating type around one' is the wordplay.
'doctor' becomes 'md' (synonyms).
'calculating type' becomes 'summer' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'around' is an insertion indicator.
'one' becomes 'i' (Roman numeral).
'md'+'summer'='mdsummer'
'mdsummer' enclosing 'i' is 'MIDSUMMER'.
'part of' acts as a link.
Can you help me to learn more?
(Other definitions for midsummer that I've seen before include "A ... Night's Dream (Shakespeare)" , "The - Marriage (Tippett)" , "21st of June" , "Fantasy in late June" , "Play with fairies and 'mechanicals'" .)