You're probably thinking of "glossolalia", though it's not really synonymous with Pentecost. Glossolalia is basically speaking in tongues or an unknown language, which is what they did on the Day of Pentecost -- and many do today. Another word for it is xenoglossia.
Pentecost, or 'The Feast of Weeks.'
myth
Ares.
dickens
cowhide
Anorak
boot
Know-it-all,
oriole
egit
A gathering
flagon