* Punch: This can be a noun (the act of striking something), a verb (to strike something), or an adjective (referring to something that punches).
* Code: This is primarily a noun, referring to a system of symbols used to represent information.
Therefore, "punch code" would most likely be considered a noun phrase, referring to a code that involves punching something.
However, depending on the context, it could also be used as a verb phrase meaning "to punch a code" or "to code by punching."
For example:
* Noun phrase: "He learned the punch code for the safe."
* Verb phrase: "You need to punch code the access panel."
Without more context, it's impossible to definitively determine the grammatical function of "punch code."