Hendekatos (ἑνδέκατος, G1734) is the ordinal numeral meaning eleventh. From hendeka (eleven) + the ordinal suffix -atos. It appears in Matthew 20:6,9 in the Parable of the Workers in the Vineyard — the workers hired 'at the eleventh hour' who receive a full day's wage — and in Revelation 21:20 describing the eleventh foundation stone of the New Jerusalem as topaz.
The 'eleventh hour' workers of Matthew 20 have given the English language a phrase — but the parable's theology goes far deeper than a last-minute opportunity. Those hired at the eleventh hour (hendekatos) — the final hour before sunset — receive the same wage as those who labored all day. The grumbling of the all-day workers and the gracious response of the landowner expose the economy of grace versus the economy of merit. The kingdom of God does not operate on a labor-for-wages basis but on the sovereign generosity of the Owner: 'I want to give the one who was hired last the same as I gave you... or are you envious because I am generous?' (Matthew 20:14–15). The thief on the cross lived his 'eleventh hour' and entered paradise (Luke 23:43). The late-coming Gentile nations are grafted in at the 'eleventh hour' of redemptive history. Hendekatos is the hour of grace that confounds calculation.