museum guard should be accepted.
It's the guard of a certain museum, though.
Even so "museum guard" is much better.
------- the museum guard " was just accepted by duo . . .
Big 4 aug 18
can we say 'múzeumnak őre nagyon fáradt' ?
If you want to structure it that way, include the definite article before the guard: A múzeumnak az őre...