The Greek adjective diēnekēs (διηνεκής) means perpetual, continual, uninterrupted, or extending without break. It is used exclusively in Hebrews (7:3; 10:1, 12, 14) in the context of the old covenant's repeated sacrifices ('offered continually, year after year') contrasted with Christ's single, perpetually effective sacrifice. The word derives from dia (through) + nēkēs (carried), suggesting something carried continuously without interruption.
The theology of diēnekēs in Hebrews is one of the most important contrasts in the New Testament. The Levitical priests stood — never sitting — and offered sacrifices diēnekēs (continually) because the work was never finished. But Christ, 'when he had offered for all time a single sacrifice for sins, sat down' (Hebrews 10:12). His sacrifice was diēnekēs in a different sense — not continuous repetition but perpetual effectiveness. By one offering He has perfected for all time those who are being sanctified (Hebrews 10:14). The standing of the old covenant priests versus the sitting of Christ is the visual theology of diēnekēs: the finished work of Christ needs no supplement, no repetition, no addition.