I understand that ghost is a translation of the German word geist. As English is based more on Latin than German, for me, spirit seems more correct.
Spirit is from the latin word spiritus which means breath. That’s where we get the word aspirate. In Greek it is pneuma from which we get pneumatic and pneumonia.The Hebrew word is ruah and its meaning is quite beautiful. God’s ruah is his breath, but his breath/spiritus/pneuma/ruah is always seen as a life giving force.
then the LORD God formed man of dust from the ground, and breathed into his nostrils the breath of life; and man became a living being. (Genesis 2:7)
Thus says the Lord GOD to these bones: Behold, I will cause breath to enter you, and you shall live. … Then he said to me, “Prophesy to the breath, prophesy, son of man, and say to the breath, Thus says the Lord GOD: Come from the four winds, O breath, and breathe upon these slain, that they may live.” (Ezekiel 37:5,9)
It is the spirit that gives life, the flesh is of no avail; the words that I have spoken to you are spirit and life. (John 6:63)
And when he had said this, he breathed on them, and said to them, "Receive the Holy Spirit. (John 20:22)
We testify to the Spirit of God being a life giving force in every Mass when we say the creed.
I believe in the Holy Spirit, the Lord, the giver of life.
-Tim-