An affectionate term used by older men for their much younger adult female lovers, friends and wives whom they adore. The young adult female sexual companion of a sugar daddy (older man) regardless of his economic class.
The term "sugardaughter" is typically given to females 18-25, however, this is arbitrary and can apply to females in their mid to late 20's as well.
In other words, If people assume your girlfriend is your daughter when they meet you and her---> she is your sugar daughter.
The word can be one word or two: "sugar daughter" or "sugardaughter" are fine.
"Oh my goodness. Your girlfriend is 21. That is old enough to be your daughter!!!"-JT
"no no no. SUGAR daughter. She's old enough to be my SUGAR daughter"-Bill