Greek: αδαπανος [adapanos] (Adjetive). Without expense, requiring no outlay, costing nothing.
αδαπανος [adapanos] appears 1 time in the NT:
(1) 1 Corinthians 9: 18
What is my reward then? Verily that, when I preach the gospel, I may make the gospel of Christ without charge, that I abuse not my power in the gospel. - αδαπανον [adapanon] Accus. sing. neuter.