Wiktionary(0.00 / 0 votes)Rate this definition: 1  smudge(Noun) A blemish; a smear. 2  smudge(Noun) Dense smoke, such as that used for fumigation. 3  smudge(Verb) To obscure by blurring; to smear. 4  smudge(Verb) To soil or smear with dirt. 5  smudge.
This smell might mean that your coolant is leaking from somewhere like a radiator or heater hose. This kind of a problem means it's a good idea to take your car into a professional. If you smell maple syrup outside the car, this might mean that you have a leaking radiator cap or that the radiator itself has a leak.
Thinkstock/Comstock/Getty Images. Coolant, also called antifreeze, is the fluid in your car that absorbs engine heat and transfers it to the radiator. Leaking coolant means that coolant is seeping out of the cooling system into other parts of the car.