What does 唰 (shua1) mean? I met the word 唰 shua1 in a Xi Yang Yang book as the sound 唰唰 one character makes while eating.  Two sources agree it is "onomat. quick slick up."  I don't know the English "quick slick up."  Google translate makes a plausible but unclear suggestion of shabu shabu for 唰唰. 

What is this word?

Here is the context.  Lazy lamb is enjoying a snack.  The panel caption tells us this is outside of the sheep village school, with a light breeze blowing (羊村“教室外,风儿轻轻吹过).
baike.com describes it as "swiftly" or "swish"... I believe it is indeed onomatopoeia.

唰 &lt;形> - Adverb 

形容迅速的样子 【swiftly】。如:唰地一下跳上墙;唰溜溜(形容极其迅速);唰啦(形容迅疾) 

Describes "swiftly" or "quickly" doing something. Like to "swiftly" jump on the wall.

唰 &lt;象> - Adjective for sound

形容迅速擦过去的声音 【swish】。如:唰唰;唰喇喇

Or describes a sound, to "swish" by something.