Sizzle sounds like the noise something makes when it sizzles, and is therefore an onomotopaeia. Other examples of this would be words likeding, moan, or chirp.
A combination of onomatopia and an adjective, it describes a quality of something at the same time denoting a sound that is associated with that quality, object, or person.
"Wow, did you see that silver Corvette, it was like VROOOM!" (VROOM would be the onomatopagative in this case)