Costing nothing, without expense; free of charge
Adapanos (from a- privative + dapanē, 'expense, cost') means 'without cost' or 'free of charge.' It appears once in the NT (1 Corinthians 9:18), where Paul explains that his reward is to preach the gospel adapanos — free of charge — not making full use of his right to financial support from those he serves. Paul had the right to receive material support (9:14), but voluntarily waived it as part of his apostolic calling.
1 Corinthians 9 is Paul's extended defense of apostolic rights alongside his voluntary renunciation of those rights. Paul's refusal to accept payment was not a universal rule but a specific, contextual choice driven by the particular situation in Corinth. His concern was that financial dependence might hinder the gospel's reception. His 'reward' was the act of free proclamation itself. This models the principle that gospel ministry must never be reduced to a commercial transaction. The grace of God is freely given (Romans 3:24 — dōrean, 'as a gift'), and those who proclaim it are to reflect that freeness in their ministry.