Twag means: Yorkshire dialect slang meaning to play truant or skive off school without permission. While rooted in traditional Northern English dialect, twag has retained some life in Yorkshire communities and. The word is mostly archaic or historical; you will only encounter it in old texts, period drama, or school history rather than current teen conversation. There is no real cause for parental concern; it is descriptive vocabulary rather than risky behaviour. As a place or proper-name reference it is purely descriptive. It is an education-system term, so usage is institutional and routine.