Objection 1. It would seem that the matter of lust is not only venereal desires and pleasures. For Augustine says (Confess. ii, 6) that "lust affects to be called surfeit and abundance." But surfeit regards meat and drink, while abundance refers to riches. Therefore lust is not properly about venereal desires and pleasures.
Objection 2. Further, it is written (Proverbs 20:1): "Wine is a lustful [Douay: 'luxurious'] thing." Now wine is connected with pleasure of meat and drink. Therefore these would seem to be the matter of lust.
Objection 3. Further, lust is defined "as the desire of wanton pleasure" [Alexander of Hales, Summ. Theol. ii, cxvli]. But wanton pleasure regards not only venereal matters but also many others. Therefore lust is not only about venereal desires and pleasures.
On the contrary, To the lustful it is said (De Vera Relig. iii [Written by St. Augustine]): "He that soweth in the flesh, of the flesh shall reap corruption." Now the sowing of the flesh refers to venereal pleasures. Therefore these belong to lust.
I answer that, As Isidore says (Etym. x), "a lustful man is one who is debauched with pleasures." Now venereal pleasures above all debauch a man's mind. Therefore lust is especially concerned with such like pleasures.
Reply to Objection 1. Even as temperance chiefly and properly applies to pleasures of touch, yet consequently and by a kind of likeness is referred to other matters, so too, lust applies chiefly to venereal pleasures, which more than anything else work the greatest havoc in a man's mind, yet secondarily it applies to any other matters pertaining to excess. Hence a gloss on Galatians 5:19 says "lust is any kind of surfeit."
Reply to Objection 2. Wine is said to be a lustful thing, either in the sense in which surfeit in any matter is ascribed to lust, or because the use of too much wine affords an incentive to venereal pleasure.
Reply to Objection 3. Although wanton pleasure applies to other matters, the name of lust has a special application to venereal pleasures, to which also wantonness is specially applicable, as Augustine remarks (De Civ. xiv, 15,16).
Source: Summa Theologica (New Advent)