noun
sending on approval; sending on approbation
A business term used in publishing and bookselling: sending books to a potential buyer with the understanding that they may be returned if not wanted. The term is domain-specific to the book trade.
見計らい送本で届いた本の中から、気に入ったものだけを購入した。
From the books sent on approval, I bought only the ones I liked.
Compound of 見計らい (みはからい, 'using one's discretion') and 送本 (そうほん, 'sending books'). The exact historical derivation is uncertain, but the term is conventionally used in the publishing industry.