nouna callup or walk-on player in something
nounan outsider in a competition with no possible hope of winning (lit., "accompanying the crown prince to study")
nounjoin one’s superior or beloved ones in doing something
nounaccompanying a child or a young person to study; fat chance – stands no chance of winning when compared with other competitors in a competition; to join in something (even if it is not relevant to them) just to keep someone company; to describe the candidates who know that they have no chance of passing even before sitting the exams