Hebrew and Greek Strong's Dictionary with all the definitions plus combined with every place that word is used in the definitions.
Complete index of every word used in both the Hebrew and Greek Strong's Dictionary in English Word order.
Hebrew and Greek Expanded Dictionary
Pentecost 1207 - deuteroprotos {dyoo-ter-op'-ro-tos}; from 1208 and 4413; second-first, i.e. (specially) a designation of the Sabbath immediately after the Paschal week (being the second after Passover day, and the first of the seven Sabbaths intervening before {Pentecost}): -- second...after the first.
Pentecost 4005 - pentekoste {pen-tay-kos-tay'}; feminine of the ord. of 4004; fiftieth (2250 being implied) from Passover, i.e. the festival of " {Pentecost} " : -- Pentecost.