Also see definition of "Concupiscence" in Word Study
Study Dictionary
Concupiscence
Concupiscence [EBD]
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 [ISBE]
CONCUPISCENCE - kon-ku'-pi-sens (epithumia): Not used in the Revised Version (British and American), but in the King James Version, Rom 7:8; Col 3:5; 1 Thess 4:5. The Greek noun, like the verb from which it comes, meaning "to yearn," "to long," "to have the heart set upon a thing," is determined in its moral quality by the source whence it springs or the object toward which it is directed. Thus, our Lord uses it to express the intensest desire of His soul (Lk 22:15). As a rule, when the object is not expressed, it refers to longing for that which God has forbidden, namely, lust. It is not limited to sexual desire, but includes all going forth of heart and will toward what God would not have us to have or be, as its use in the Septuagint of the Ten Commandments clearly shows, for "Thou shalt not covet" (Ex 20:17).H. E. Jacobs
Also see definition of "Concupiscence" in Word Study