Outsider

Part of speech: noun (n.)

1. One not belonging to the concern, institution, party, etc., spoken of; one disconnected in interest or feeling. [Recent] A. Trollope.

2. A locksmith's pinchers for grasping the point of a key in the keyhole, to open a door from the outside when the key is inside.

3. A horse which is not a favorite in the betting. [Cant]