A Greek noun meaning end, goal, purpose, outcome, conclusion, tax/toll. From the root idea of reaching a point of completion or consummation. It does not necessarily mean 'termination' but often means 'fulfillment, reaching the intended goal.' The related verb teleō means 'to complete, accomplish' and the adjective teleios means 'perfect, mature, complete.'
Paul's declaration that 'Christ is the end (telos) of the law' (Romans 10:4) is one of the most theologically debated phrases in the New Testament. Does telos mean Christ terminated the law, or that He is the law's goal and fulfillment? The best answer: both. Christ is where the law was always pointing (its goal) and therefore where its condemnatory function ends (its terminus) for those who believe. Jesus' cry 'It is finished' (tetelestai, John 19:30) uses the same root — the work of redemption has reached its telos, its intended completion. Peter speaks of the 'outcome (telos) of your faith — the salvation of your souls' (1 Peter 1:9). Faith has a destination, and telos assures us we will arrive.