According to Merriam-Webster dictionary, the first appearance of the word "ghost" was in 1606, five years before the Authorized Version was released in 1611. The word "ghost" appears in the KJV 109 times in 108 verses. This is the first appearance:
Gen_25:8 Then Abraham gave up the ghost, and died in a good old age, an old man, and full of years; and was gathered to his people. http://www.merriam-webster.com/dictionary/ghost
According to the same source the word "spirit" first appeared in 1608:
It occurs 505 times in 456 verses. This is the first occurrence:
Gen_1:2 And the earth was without form, and void; and darkness was upon the face of the deep. And the Spirit of God moved upon the face of the waters.
However I notice that the Wycliffe Bible, from the 1300s uses the word "Spiryt" a few times. IE:
Gen 1:2 Forsothe the erthe was idel and voide, and derknessis weren on the face of depthe; and the Spiryt of the Lord was borun on the watris.
The word "breath" only occurs 42 times in 42 verses. Here is the first occurrence:
Gen_2:7 And the LORD God formed man of the dust of the ground, and breathed into his nostrils the breath of life; and man became a living soul.
My question is, in 1611 when these words were coined and used in the KJV were "ghost" and" "spirit" simply synonyms of each other? IE: Are the KJV authors distinguishing "Spirit" from "Ghost" in this verse or just varying it up?:
Joh_1:33 And I knew him not: but he that sent me to baptize with water, the same said unto me, Upon whom thou shalt see the Spirit descending, and remaining on him, the same is he which baptizeth with the Holy Ghost.
And what about "breath"? They seem to be used in parallel:
Job_27:3 All the while my breath [H5397] is in me, and the spirit [H7307] of God is in my nostrils;
נְשָׁמָה neshâmâh nesh-aw-maw' From H5395; a puff, that is, wind, angry or vital breath, divine inspiration, intellect or (concretely) an animal: - blast, (that) breath (-eth), inspiration, soul, spirit. Total KJV occurrences: 24
רוּחַ rûach roo'-akh From H7306; wind; by resemblance breath, that is, a sensible (or even violent) exhalation; figuratively life, anger, unsubstantiality; by extension a region of the sky; by resemblance spirit, but only of a rational being (including its expression and functions): - air, anger, blast, breath, X cool, courage, mind, X quarter, X side, spirit ([-ual]), tempest, X vain, ([whirl-]) wind (-y). Total KJV occurrences: 378
So what did these words mean to the KJV translators? Were they all synonyms of each other? If so, why muddy the waters? Why translate as "ghost" sometimes and "spirit" at other times? Why not just retain "breath" as all other languages seemed to do prior to English translations of the scriptures?