window tax
noun /ˈwɪndəʊ tæks/
/ˈwɪndəʊ tæks/
[uncountable]- a historical tax that British people had to pay according to how many windows they had in their houses. It was in use between 1675 and 1851. It is still possible to see old houses in Britain that had their windows filled in with stone, bricks, etc. in order to save tax.