G5446–φυσικός–phusikos

This then is the reason why God gave them up to vile passions. For not only did the women among them exchange the natural use of their bodies for one which is contrary to nature, but the men also,

φυσικὴν phusikēn “natural”

in just the same way--neglecting that for which nature intends women--burned with passion towards one another, men practising shameful vice with men, and receiving in their own selves the reward which necessarily followed their misconduct.

φυσικὴν phusikēn “natural”

But these men, like brute beasts, created (with their natural instincts) only to be captured or destroyed, are abusive in matters of which they are ignorant, and in their corruption will perish,

φυσικὰ phusika “as creatures of instinct”