gluttenous, greedy, lewd, lecher
饞 centers on excessive, uncontrolled desire: gluttony for food, greed for possessions, or lewd, lecherous craving. The common thread is an insatiable appetite that goes beyond normal limits.
饞 combines the food radical 飠 with 毚, which likely contributes the sound and carries a sense of cunning or insatiable appetite. The exact historical development of 毚 is uncertain, but the character as a whole expresses excessive desire, especially for food.
The left side 飠 (food) and the right side 毚 (a complex shape suggesting two rabbits 兔 under a roof) hint at an insatiable hunger: imagine a person so greedy they would devour two rabbits at once, their appetite extending to all kinds of excess.
For サン, picture a glutton at a feast grabbing three (三, さん) plates at once, unable to stop: 三 -> サン, and the food radical 飠 reinforces the scene of overindulgence.