A conservative religious movement within evangelical Protestant Christianity traced back to the early 1900's in the United States and involving belief in a "baptism of the Holy Spirit" as a special blessing available to all Christians, but conclusively evidenced in the life of the Christian only through "speaking in tongues" (American Heritage Dictionary "gift of tongues"), also sometimes referred to by the Greek term glossolalia. Pentecostalism has a tradition of separatism resulting in numerous Pentecostal denominations and independent congregations. In general, it shares with Christian fundamentalism a strong affinity for biblical literalism.
(see TheocracyWatch.org "Pentecostals")
usage. Pentecostalism differs from the Charismatic movement. As terms, "Pentecostals" and "Charismatics" are not synonymous.
note. Pentecostalism is a global movement, and the estimations of the number of its adherents range from approximately 60,000,000 to approximately 120,000,000. The largest Protestant Christian congregation in the world is a Pentecostal church in Seoul, South Korea (see Yoido Full Gospel Church website).
encyclopedic entry. see V. Synan, "Pentecostalism," Elwell Evangelical Dictionary.