Pentecost /ˈpɛntɪˌkɑːst/ noun Learner's definition of PENTECOST
[noncount]
: a Christian holiday on the seventh Sunday after Easter that celebrates the appearance of the Holy Spirit to the apostles五旬节，神灵降临节（基督教节日，在复活节后的第七个周日，以庆祝神灵降临在使徒身上） — called also (British) Whit Sunday