Sleazy. A person or situation with questionable motives. A con.
Use 1. so and so is being scammable.
Use 2. something is done in a scammable fashion.
Use 3. an exclamation.
1. That boy is playing with his gameboy at the table in this nice restaurant, how scammable.
2. betties hang out in a scammable fashion at skateparks.
3. girl one: look at that blonde chick.
girl two: scammable.