In Dutch it's a metasyntactic variable (like foo). Most commonly used as a replacement for "stuff", or "things".
In Thai, it's squid. Or that's my best guess. Since all dishes with squid in them also contain the word "meuk" in Thai.
anthropod spreads her knowledge through the Chatterbox and informs me that: "plaa meuk is Thai for squid. Plaa is fish. The two words are used together."