Pronunciation: (pen"ti-kô'stul, -stl, -kos'tul, -tl-),[key] —adj. 1. of or pertaining to Pentecost.
2. noting or pertaining to any of various Christian groups, usually fundamentalist, that emphasize the activity of the Holy Spirit, stress holiness of living, and express their religious feelings uninhibitedly, as by speaking in tongues.
—n. Also called Pen"te•cos'tal•ist. a member of any Pentecostal denomination.