Three linked works I record in test (7)
I believe the answer is:
trilogy
'three' is the definition.
(thesaurus)
'i record in test' is the wordplay.
'record' becomes 'log' (log is a kind of record).
'in' is an insertion indicator.
'test' becomes 'try' (synonyms).
'i'+'log'='ilog'
'ilog' put within 'try' is 'TRILOGY'.
'linked works' is the link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for trilogy that I've seen before include "Set of three literary or dramatic works" , "Group of three linked works" , "Three-volume work" , "Group of three related works" , "Work in three parts" .)