@f0x jokingly, people sometimes say 'linner', but also, there is a dinner vs supper thing.

Dinner can also mean 'largest meal', especially in farming communities, and with older people. If the midday meal is small, it's lunch, if the evening meal is small, it's super, and then dinner is whichever is bigger. This is mostly a farming communities thing now, though, and most Americans today expect that dinner and supper are the same meal.