An advisor or manager to a person occupying a position or office to which the speaker believes the holder does not possess the typical qualifications and/or experience.
One who handles something (especially manually) or someone.
A subroutine that handles a particular situation such as an event or exception.
A controller, trainer, someone who handles a specified thing, animal or person (especially a prizefighter).
A supervisory political officer responsible for ideological education and organization.