complimentary copy; gift book
A book presented as a gift, often by the author or publisher; can be a free copy given for review or as a token of appreciation.
I received a complimentary copy from the author.
This book is a gift copy from the publisher.
Compound of 贈呈 (presentation, gift) and 本 (book). The exact historical derivation is uncertain, but the word follows standard Sino-Japanese compounding patterns.