A person who is running in an election.
A person who is applying for a job.
A participant in an examination.
Something or somebody that may be suitable.
A gene which may play a role in a given disease.
To stand as a candidate for an office, especially a religious one.
(chiefly in jargon and NNES) To make or name (something) a candidate (for use, for study as a next project, for investigation as a possible cause of something, etc).