πεντηκοστός, -ή, -όν [in LXX for חֲמִישִׁי, Refs חֲמִישִׁי, Lev.25:10-11, 4Ki.15:23 15:27; 1Ma.4:1-61, 2Ma.14:4; ἡ π., Refs Tob.2:1, 2Ma.12:32 * ;] fiftieth. As subst., ἡ π.; __(a) (sc. μερίς), at Athens, a tax of two per cent.; __(b) (sc. ἡμέρα, i.e. the fiftieth day after the Passover), Pentecost, the second of the three great Jewish feasts (To, 2Mac, ll. with; ἑορτὴ ἑβδομάδων, Refs Deu.16:10, al.) : Act.2:1 20:16, 1Co.16:8.† (AS)
Thayer:
1) the second of the three great Jewish feasts, celebrated at Jerusalem yearly, the seventh week after the Passover, in grateful recognition of the completed harvest
Literal: Pentecost = "the fiftieth day"
πεντηκοστή
pentēkostē
pen-tay-kos-tay'
Feminine of G4004; fiftieth (G2250 being implied) from Passover, that is, the festival of “pentecost”
ἡμέρα
hēmera
hay-mer'-ah
Feminine (with G5610 implied) of a derivative of ἧμαι hēmai (to sit; akin to the base of G1476) meaning tame, that is, gentle; day, that is, (literally) the time space between dawn and dark, or the whole 24 hours (but several days were usually reckoned by the Jews as inclusive of the parts of both extremes); figuratively a period (always defined more or less clearly by the context)
KJV Usage: age, + alway, (mid-) day (by day, [-ly]), + for ever, judgment, (day) time, while, years.
G839 αὔριοναὔριον
aurion
ow'-ree-on
From a derivative of the same as G109 (meaning a breeze, that is, the morning air); properly fresh, that is, (adverbially with ellipsis of G2250) tomorrow
KJV Usage: (to-) morrow, next day.
G1887 ἐπαύριονἐπαύριον
epaurion
ep-ow'-ree-on
From G1909 and G839; occuring on the succeeding day, that is, (G2250 being implied) tomorrow
KJV Usage: day following, morrow, next day (after).
G1966 ἐπιοῦσαἐπιοῦσα
epiousa
ep-ee-oo'-sah
Feminine singular participle of a compound of G1909 and εἷμι heimi (to go); supervening, that is, (G2250 or G3571 being expressed or implied) the ensuing day or night
KJV Usage: following, next.
G2184 ἐφήμεροςἐφήμερος
ephēmeros
ef-ay'-mer-os
From G1909 and G2250; foraday (“ephemeral”), that is, diurnal
KJV Usage: daily.
G2522 καθημερινόςκαθημερινός
kathēmerinos
kath-ay-mer-ee-nos'
From G2596 and G2250; quotidian
KJV Usage: daily.
G3314 μεσημβρίαμεσημβρία
mesēmbria
mes-ame-bree'-ah
From G3319 and G2250; midday; by implication the south
KJV Usage: noon, south.
G3561 νουμηνίανουμηνία
noumēnia
noo-may-nee'-ah
Feminine of a compound of G3501 and G3376 (as noun by implication of G2250); the festival of newmoon
KJV Usage: new moon.
G3574 νυχθήμεροννυχθήμερον
nuchthēmeron
nookh-thay'-mer-on
From G3571 and G2250; a day and night, that is, full day of twenty four hours
KJV Usage: night and day.
G3637 ὀκταήμεροςὀκταήμερος
oktaēmeros
ok-tah-ay'-mer-os
From G3638 and G2250; an eightday old person or act
KJV Usage: the eighth day.
G4287 προθέσμιοςπροθέσμιος
prothesmios
proth-es'-mee-os
From G4253 and a derivative of G5087; fixedbeforehand, that is, (feminine with G2250 implied) a designated day
KJV Usage: time appointed.
G4594 σήμερονσήμερον
sēmeron
say'-mer-on
Neuter (as adverb) of a presumed compound of the article G3588 (“tau” changed to “sigma”) and G2250; on the (that is, this) day (or night current or just passed); genitively now (that is, at present, hitherto)