Conservator has short form essentially about introduction to antiquities (7)
I believe the answer is:
curator
'conservator' is the definition.
(synonyms)
'short form essentially about introduction to antiquities' is the wordplay.
'short' becomes 'curt' (synonyms).
'essentially' says to take the centre.
'about' means one lot of letters goes inside another.
'introduction to' suggests taking the first letters.
The middle of 'form' is 'or'.
The first letter of 'antiquities' is 'a'.
'curt'+'or'='curtor'
'curtor' going around 'a' is 'CURATOR'.
'has' acts as a link.
(Other definitions for curator that I've seen before include "Museum officer" , "Person in charge of a museum" , "Guardian" , "Cultural employee" , "Custodian - caretaker" .)