If you want to express something so unbelievable that it must have been a special effect, you have a new word to add to your vocabulary.

It's "Duang", an onomatopoetic word which doesn't correlate with any particular Chinese character and refers to special effects.

A video parody adapted from a shampoo commercial featuring Hong Kong actor Jackie Chan went viral online, leading Internet users to coin the word.

The video begins with Chan flashing his black, sleek hair, which would have been flawless except that it was not his real hair, to the tune of online hit, "My Skating Shoes", known for its coarse melody and the singer's strong southern Mandarin dialect.

Next, a smug Chan confesses, to the repetitive, rhythmical sounds of "Duang", "I refused to endorse this product when they first came to me because of my thin hair, but the director insisted, saying special effects could be used to make my hair look healthy on the screen. Now you see. It's all special effects. It's not real."

The original advertisement became the target of regulators' crackdown for overhyping the effects of the shampoo after it was broadcast in 2004.