Is ㄙㄨㄚˋ (sua4) for the character 嘴 from another Chinese dialect or language?
紲喙 (suà-tshuì)
  
  合口味。
  Palatable
  
  形容東西合胃口、好吃，一口接一口，愈吃愈想吃。
  The term describes that the food is so delicious that you want to eat more.




紲 is a substitute character (替代字) and means "continue".



source: 臺灣閩南語常用詞辭典