truant: [13] A truant was originally a ‘beggar’ or ‘vagrant’. The word was borrowed from Old French truant ‘vagabond’, which in turn came from Gaulish trugant- (amongst its Celtic relatives are Gaelic trudanach ‘vagabond’ and Welsh truan ‘wretched’). The word was not applied to absconding schoolchildren until the 15th century. [truant etymology, truant origin, 英语词源]