(1) The evening meal, which is ordinarily the last meal of the day.
In the middle ages "supper" referred to a light meal following dinner. Until the eighteenth century dinner was the midday meal. Go figure.
(2) The evening meal. Also known as "dinner".
(3) A light meal served in early evening if the largest meal is at midday, though sometimes supper is served late in the evening, near bedtime
We called it supper. Sometimes "dinner" is just the biggest meal of the day, and can happen at noon. But really, supper comes when you can get it, usually in the evening these days.