Bible: Begotten Only Son

Repeated words found across different books in the Bible (KJV):
John 1:18
No man hath seen God at any time; the only begotten Son, which is in the bosom of the Father, he hath declared him.

John 3:16
For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life.

John 3:18
He that believeth on him is not condemned: but he that believeth not is condemned already, because he hath not believed in the name of the only begotten Son of God.

Heb 11:17
By faith Abraham, when he was tried, offered up Isaac: and he that had received the promises offered up his only begotten son,

1Jn 4:9
In this was manifested the love of God toward us, because that God sent his only begotten Son into the world, that we might live through him.