an expert who gives advice
"an adviser helped students select their courses"
"the United States sent military advisors to Guatemala"
One who offers advice.
"After failing her driving test, Sarah called a local instructor to act as an advisor on how she can improve her technique."
In plain English: An advisor is someone who gives you advice to help you make good decisions.
"She asked her financial advisor for help choosing the right investment plan."
Usage: An advisor is a person who gives guidance or counsel to another individual or group. Use this term for anyone in a role where their primary function is to offer expert advice rather than execute tasks themselves.
The word advisor comes from combining the verb advise with the agent suffix -or to denote a person who gives advice. It entered English as a straightforward formation describing someone whose role is to offer counsel.