I think the names of meals vary according to the part of the country. Growing up, we had breakfast, dinner , tea, and, once we stayed up a bit later, supper. Dinner was a two course cooked meal around 12.30 and my mum continued this until her dying day. Tea when we were little was bread and spread and cake. Supper might be a drink and a biscuit or fruit cake.
As we grew older we came home from school absolutely starving, so tea became more substantial, something on toast or a salad, followed by bread and jam and cake or tinned fruit. Never called high tea, though in our house. We were poor, not posh.
Nowadays, we have a salad or sandwich at lunch time, and a cooked main course at night, sometimes followed by a yoghurt, with a snack later on, fruit or cheese and biscuits, or just a drink.
On Sundays we revert to a traditional roast dinner at 1pm, then a cup of tea and cake at 4pm, to keep us going till 7 or 8pm when we have ham rolls( we call it Sunday supper, though DH says Sabbath rolls ).
I hate the term “supper” to mean an evening meal, as it is in the south.