Guarantee, Assurance, Warranty
noun, verbal noun
Giving evidence (or a guarantee) that you will preserve something, is giving a guarantee, assurance, or warranty. This word is used when the emphasis is on taking responsibility for something, as in a guarantor, a product warranty, or quality assurance.
ほしょう
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
保証書を失くさないようにしてください。
Please keep the warranty certificate safe.
この商品には一年間の保証が付いています。
This product comes with a one-year warranty.
私はワニカニのライフタイムメンバーですが、トーフグが五年後もあるなんて保証はないから本当にライフタイムでワニカニが使えるなんて思っていませんよ。
I am a lifetime member of WaniKani, but I don't really think I can use it for life, as there is no guarantee that Tofugu will still be around in five years.