as it it used here,
comes from a Greek word meaning,
The body (as opposed to the soul or spirit); human nature, with its physical and moral frailities and passions; a human being.

This I say then, Walk in the Spirit, and ye shall not fulfill the lust of the flesh. For the flesh lusteth against the Spirit, and the Spirit against the flesh: and these are contrary the one to the other: so that ye cannot do the things that ye would. But if ye be led of the Spirit, ye are not under the law.
Galatians 5:16-18