Chresis (G5540) comes from chraomai (to use) and refers to the use or function of something — its natural application. Appearing only in Romans 1:26-27, Paul uses chresis to describe 'natural use' in the context of sexual ethics: women who 'exchanged the natural use [chresis] for that which is against nature' and men who 'left the natural use [chresis] of the woman.' The word carries forensic weight in one of the NT's most direct discussions of sexual immorality as a consequence of idolatry.
The chresis passage in Romans 1:24-27 is embedded in Paul's diagnosis of human sinfulness as rooted in the suppression of truth about God (Rom 1:18-25). The exchange of natural chresis is presented as a symptom, not the root: the root is the exchange of the Creator for creatures (1:25). When humans suppress the knowledge of God, the distortion flows downward through every aspect of human life, including sexuality. The theological framework is creation order: God designed use (chresis) to reflect His purposes. The NT calls believers to present their bodies as 'living sacrifices' (Rom 12:1) — the right chresis of the body is worship, offered to the Creator.