Pentecost

Boyd’s Bible Dictionary:

(fiftieth day). The Hebrew harvest-home festival, celebrated on fiftieth day from the Passover, or on the date of the giving of the law at Sinai (Ex. 23:16; 34:2216And the feast of harvest, the firstfruits of thy labors, which thou hast sown in the field: and the feast of ingathering, which is in the end of the year, when thou hast gathered in thy labors out of the field. (Exodus 23:16)
22And thou shalt observe the feast of weeks, of the firstfruits of wheat harvest, and the feast of ingathering at the year's end. (Exodus 34:22)
; Lev. 23:15-2215And ye shall count unto you from the morrow after the sabbath, from the day that ye brought the sheaf of the wave offering; seven sabbaths shall be complete: 16Even unto the morrow after the seventh sabbath shall ye number fifty days; and ye shall offer a new meat offering unto the Lord. 17Ye shall bring out of your habitations two wave loaves of two tenth deals: they shall be of fine flour; they shall be baken with leaven; they are the firstfruits unto the Lord. 18And ye shall offer with the bread seven lambs without blemish of the first year, and one young bullock, and two rams: they shall be for a burnt offering unto the Lord, with their meat offering, and their drink offerings, even an offering made by fire, of sweet savor unto the Lord. 19Then ye shall sacrifice one kid of the goats for a sin offering, and two lambs of the first year for a sacrifice of peace offerings. 20And the priest shall wave them with the bread of the firstfruits for a wave offering before the Lord, with the two lambs: they shall be holy to the Lord for the priest. 21And ye shall proclaim on the selfsame day, that it may be an holy convocation unto you: ye shall do no servile work therein: it shall be a statute for ever in all your dwellings throughout your generations. 22And when ye reap the harvest of your land, thou shalt not make clean riddance of the corners of thy field when thou reapest, neither shalt thou gather any gleaning of thy harvest: thou shalt leave them unto the poor, and to the stranger: I am the Lord your God. (Leviticus 23:15‑22); Num. 28). Christ died on the day of the Passover. Fifty days later, after His resurrection and ascension to glory, on the day of Pentecost, the Church was formed by the descent and indwelling of believers by the Holy Spirit (Acts 2:1-141And when the day of Pentecost was fully come, they were all with one accord in one place. 2And suddenly there came a sound from heaven as of a rushing mighty wind, and it filled all the house where they were sitting. 3And there appeared unto them cloven tongues like as of fire, and it sat upon each of them. 4And they were all filled with the Holy Ghost, and began to speak with other tongues, as the Spirit gave them utterance. 5And there were dwelling at Jerusalem Jews, devout men, out of every nation under heaven. 6Now when this was noised abroad, the multitude came together, and were confounded, because that every man heard them speak in his own language. 7And they were all amazed and marvelled, saying one to another, Behold, are not all these which speak Galileans? 8And how hear we every man in our own tongue, wherein we were born? 9Parthians, and Medes, and Elamites, and the dwellers in Mesopotamia, and in Judea, and Cappadocia, in Pontus, and Asia, 10Phrygia, and Pamphylia, in Egypt, and in the parts of Libya about Cyrene, and strangers of Rome, Jews and proselytes, 11Cretes and Arabians, we do hear them speak in our tongues the wonderful works of God. 12And they were all amazed, and were in doubt, saying one to another, What meaneth this? 13Others mocking said, These men are full of new wine. 14But Peter, standing up with the eleven, lifted up his voice, and said unto them, Ye men of Judea, and all ye that dwell at Jerusalem, be this known unto you, and hearken to my words: (Acts 2:1‑14)).

Concise Bible Dictionary:

This name which signifies “fiftieth” is found only in the New Testament: it corresponds to the FEAST OF WEEKS. From the waving of the sheaf of firstfruits fifty days were counted, and on the day after the seven sabbaths the feast was kept. A new meat offering of two loaves baken with leaven was offered; also seven lambs, one bullock, and two rams for a burnt offering, with their meat and drink offerings “even an offering made by fire of sweet savor unto the Lord.” Also one kid of the goats for a sin offering; and two lambs for a peace offering. It was proclaimed a holy convocation, in which no servile work was to be done (Lev. 23:15-2115And ye shall count unto you from the morrow after the sabbath, from the day that ye brought the sheaf of the wave offering; seven sabbaths shall be complete: 16Even unto the morrow after the seventh sabbath shall ye number fifty days; and ye shall offer a new meat offering unto the Lord. 17Ye shall bring out of your habitations two wave loaves of two tenth deals: they shall be of fine flour; they shall be baken with leaven; they are the firstfruits unto the Lord. 18And ye shall offer with the bread seven lambs without blemish of the first year, and one young bullock, and two rams: they shall be for a burnt offering unto the Lord, with their meat offering, and their drink offerings, even an offering made by fire, of sweet savor unto the Lord. 19Then ye shall sacrifice one kid of the goats for a sin offering, and two lambs of the first year for a sacrifice of peace offerings. 20And the priest shall wave them with the bread of the firstfruits for a wave offering before the Lord, with the two lambs: they shall be holy to the Lord for the priest. 21And ye shall proclaim on the selfsame day, that it may be an holy convocation unto you: ye shall do no servile work therein: it shall be a statute for ever in all your dwellings throughout your generations. (Leviticus 23:15‑21)). The Israelites came with their free-will offerings unto Jehovah, according as He had blessed them. See OFFERINGS.
The feast is typical of the presentation of the saints in the power and sanctification of the Holy Spirit. It was to be a day of universal rejoicing before the Lord (Deut. 16:9-129Seven weeks shalt thou number unto thee: begin to number the seven weeks from such time as thou beginnest to put the sickle to the corn. 10And thou shalt keep the feast of weeks unto the Lord thy God with a tribute of a freewill offering of thine hand, which thou shalt give unto the Lord thy God, according as the Lord thy God hath blessed thee: 11And thou shalt rejoice before the Lord thy God, thou, and thy son, and thy daughter, and thy manservant, and thy maidservant, and the Levite that is within thy gates, and the stranger, and the fatherless, and the widow, that are among you, in the place which the Lord thy God hath chosen to place his name there. 12And thou shalt remember that thou wast a bondman in Egypt: and thou shalt observe and do these statutes. (Deuteronomy 16:9‑12)), and was the commencement of the ingathering of the harvest. It is not mentioned in Ezekiel’s future feasts, because it has been fulfilled in the present interval in God’s dealings with Israel (compare John 7:37-3937In the last day, that great day of the feast, Jesus stood and cried, saying, If any man thirst, let him come unto me, and drink. 38He that believeth on me, as the scripture hath said, out of his belly shall flow rivers of living water. 39(But this spake he of the Spirit, which they that believe on him should receive: for the Holy Ghost was not yet given; because that Jesus was not yet glorified.) (John 7:37‑39)). See FEASTS.

Strong’s Dictionary of Greek Words:

Greek:
πεντηκοστή
Transliteration:
pentekoste
Phonic:
pen-tay-kos-tay’
Meaning:
feminine of the ordinal of 4004; fiftieth (2250 being implied) from Passover, i.e. the festival of "Pentecost"
KJV Usage:
Pentecost

Jackson’s Dictionary of Scripture Proper Names:

fiftieth

Potts’ Bible Proper Names:

Fiftieth:―festival celebrated on fiftieth day from Passover, Acts 2:1. {Quinquagesimus}