Bid to include one record in triad (7)
I believe the answer is:
trilogy
'triad' is the definition.
(trilogy is a kind of triad)
'bid to include one record' is the wordplay.
'bid' becomes 'try' (I've seen this in other clues).
'to include' is an insertion indicator.
'one' becomes 'i' (Roman numeral).
'record' becomes 'log' (logging is a kind of recording).
'i'+'log'='ilog'
'try' going around 'ilog' is 'TRILOGY'.
'in' is the link.
(Other definitions for trilogy that I've seen before include "Group of three novels, films, etc" , "Group of three linked works" , "collected works" , "Triad" , "Three-volume work" .)