Definition of holy ghost in English English dictionary
One of the three figures of the Holy Trinity, the others being the Father (God) and the Son (Jesus), known as the Spirit of God
The Holy Ghost is the same as the Holy Spirit. The Holy Spirit. the Holy Ghost God in the form of a spirit according to the Christian religion = Holy Spirit
the third person in the Trinity; Jesus promised the Apostles that he would send the Holy Spirit after his Crucifixion and Resurrection; it came on Pentecost