[Dragon FangX]

For me, these are what usually qualify as a bimbo:

1. Over exaggerated figure, particularly in breasts, butt and hips.

2. A preference to have sexual intercourse when possible.

3. Limited mental ability, though can be proficient in certain tasks.

4. An affiliation to looking attractive, including but not limited to heavy use of make up and revealing clothing.

5. Blond hair and tan skin.

If a character has 3 out of 5 of those traits, that's a bimbo to me so long as #3 is one of the three.