I love the idea of teol versus táir. Funnily, as teachers, my parents used to discriminate between those pupils 'blaggarts' and 'slooters'.
'blaggarts' - were the pupils who got up to badness but were totally obvious about it and usually accepted any punishment pretty stoically.
'slooters' - were the pupils who did bad things in an underhand way and never owned up to their crimes, and always acted outraged at any punishments they were given.
My parents always preferred the blaggarts to the slooters
And slooter - what sort of word is that? I doubt it's English in origin.
Is fearr dhá theanga ná ceann amháin…