“Seldom” means not often or rarely.

You can think of it as something that happens, but only once in a while, not regularly. For example:

  • “I seldom eat fast food” = I almost never eat fast food.
  • “They seldom watch television these days” = They don’t watch TV very often.

It’s a slightly formal or literary word; in everyday speech people more often say “rarely” or “not very often,” but the meaning is basically the same.