Concupiscence

Concupiscence - (Easton's Bible Dictionary)

Desire, Rom. 7:8 (R.V., "coveting"); Col. 3:5 (R.V., "desire"). The "lust of concupiscence" (1 Thess. 4:5; R.V., "passion of lust") denotes evil desire, indwelling sin.

Concupiscence - (Webster's 1828 Dictionary)

CONCUPISCENCE, n. [L., to covet or lust after, to desire or covet.] Lust; unlawful or irregular desire of sexual pleasure. In a more general sense, the coveting of carnal things, or an irregular appetite for worldly good; inclination for unlawful enjoyments.

We know even secret concupiscence to be sin.

Sin, taking occasion by the commandment, wrought in me all manner of concupiscence. Rom 7.