Tweenie
This term has started to appear in British newspapers, though it isn’t that new, nor is it British in origin. Its sudden visibility has been due to the appointment of Andi Peters, who used to be the friendly face of BBC children’s television, to help run Channel 4’s children’s programming. In particular, he is to revitalise the tweenie zone, the time between 6pm and 7pm when those aged between about 10 and 15 watch television most. The term seems to be fairly common marketing jargon in the broadcasting field for this age range, who don’t regard themselves as children and so don’t want to watch programmes for younger viewers (sometimes called tweenagers), but are still thought too young to understand and enjoy material for adults. The name is a diminutive form of the second part of between, which may have been influenced by the much older and now defunct British English word tweeny for a “between maid”, a very junior servant who helped both cook and parlourmaid, so named because she work both downstairs in the servant quarters and upstairs and so was continually moving between floors. The limited evidence I have suggests the new meaning is of North American origin, most probably Canadian.