没错,“What do you mean by…?〔你(说的……)是什么意思?〕”是个固定句型,意思就相当于“What's the meaning of…?” 你只要平时多造句就会慢慢习惯的. 如: What do you mean by " tofu "? = What's the meaning of "tofu"?
翻译:你认为垃圾食品的含义是什么? what do you mean by junk food? = What's the meaning of junk food? =What does junk food mean? what do you mean by固定句型,你觉得/认为...是什么意思?”