This is the 15492nd most frequent Russian word.
предшественника
"Predecessor."
Here, 'предшественник' indicates a previous version or instance, in this case, referring to an earlier book in comparison to the current one.
Эта книга гораздо более интересная, чем её предшественник.
This book is much more interesting than its predecessor.
'Предшественник' here denotes someone who conducted prior work or research that the subject is building upon.
Молодой учёный с уважением вспоминал предшественника, от чьих исследований он отталкивался.
The young scientist recalled with respect the predecessor from whose research he started his work.
In this sentence, 'предшественник' refers to an earlier model of the car that is being improved upon.