The word "inerrant" is very closely related to the word "infallible". The Bible is infallible in total, and inerrant in every part. Inerrancy means that not just all the truth in the Bible is God's word, but every scripture down to the dotting of the "i" and the crossing of the "t" is the embodied Revelation of Almighty God, and is entirely true and never false in all it affirms, whether it be in doctrine, or ethics, or science, or history, or the future, or whatever the case may be. Jesus said,

Matt 5:18 "For assuredly, I say to you, till heaven and earth pass away, one jot or one tittle will by no means pass from the law till all is fulfilled.

Jn 10:35 "...the Scripture cannot be broken.