One who has been brainwashed into preforming actions (such as assassination) upon recieving a special code word or phrase. The candidate acts and behaves normally before recieving the trigger, with no knowledge of what he will do, or what he has done while under the influence of mind control.
The assassination of the president was carried out by a manchurian candidate, under the control of a foreign power.
by laguna72 July 31, 2004
Reference to one’s own penis during an unexpected or unwanted erection
“I saw this hot chick at the bar and The Manchurian Candidate went rock hard, it was out of control dude, the thing has a mind of its own”

“I was talking to Betty at the swimming pool, when all of the sudden The Manchurian Candidate sprung into action… I was so embarrassed”
by tl77 November 24, 2010
An highly influential official or politician who has been placed in her/his position by a foreign power with a view to influencing or even dominate another nation.
Many people in the US and Europe now see president Trump as a Manchurian Candidate placed in his position by Putin and under the secret command of the Russian president and his power clique.
by Wryface July 12, 2017
You've seen a radio-active Spider-Man, but you haven't seen a radio-active Spider-Man that's in love with his mother. Sexy.
"Coming to a theater near you, Spider-Manchurian Candidate."
by AnotherJon July 29, 2006