the best translation supposed to be "高级顾问" .
senior means 高级, "高"means "high","级"means "level" ,Together means "high level ";
here "顾问" : 顾 in ancient Chinese means "look",as the meaning developed ,it contain the meaning of "look afer, engage in, exercise the profession of ..."
问 means "inquire,ask,refer to ",
so here 顾问 means "look around then find out the right person to ask" . The meaning developed further, became"Senior Advisor" today.
This word 顾问 is the verb in the noun form .