>In the pioneer camps in former Soviet Union there were these kind of meals:
>
>9am - breakfast
>2pm - dinner
>5:30pm - light meal (don't have a word in English?)
>8pm - supper

The light meal you mention would be called snack here. There's a funny connection between names of meals in Serbian and Russian:

doruchak (s) - zavtrak (r) - breakfast
ruchak (s) - obed (r) - lunch; but word "obed" means "meal" in Serbian :)
vechera (s) - uzhin (r) - supper. We have double ties here - "vecher" means "evening" in Russian, and "uzhina" means "snack" in Serbian :)

(correct me if I got some Russian wrong - I tried to refresh it lately, but mathematical texts don't mention meals :)