Translation:You eat noodles.
For those who are interested in learning traditional form:
In simplified writing system, 面 can have two main meanings: "noodle" and "face".
When talking about "noodle," it is 麵 in traditional form, but when talking about "face" both system use "面."
Combining the complicated characters into simpler characters with similar pronunciation was also an approach to form the simplified characters.
In my Mandarin class, we were taught that noodles had two characters, though I can't remember what the second one was. We were taught two foodstuffs containing mian (sorry for no tone marker) - bread and noodles, because they both contain an ingredient which is the same. Is it common to only use mian to say noodles?
吃麵 (excuse the traditional, I will include pīnyīn as best I can) chī miàn is almost phrasal, and yeah you can say 麵 miàn on its own, but if it isn't clear based on context, then you can use the two character alternative 麵條 miàn tiáo (flour strips), but conversely, you're more likely to say 吃麵 with no 條 this goes the same with 吃飯 chī fàn and 米飯. Mî fàn.