What is the meaning of a timeless essay?

Perhaps it means in the sense of, it will stand the test of time?

As in, 100 years in the future, someone could read it and say, “Oh ho, I get that.” well, maybe not.

I would read it as something that has relevance to anybody at any point in time.

Dunno if that helps. Good luck!

By definition it would appear to be an essay that transcends time. I.E. it will always be relevant or have an impact or “something to say” regardless of time.

An example might include Virginia Woolf’s “A Room of One’s Own”, an extended essay written, in part, as a discussion of whether women are capable of producing the same quality of work as William Shakespeare. It could be considered timeless in that gender roles and the “battle of the sexes” will always be relevant to society.

A timeless essay is one that is relevant beyond the time period in which it’s written. Whether it was written in the 1860’s or 1700’s or 2000, the content of the essay resonates with the reader as relevant as contemporary.

Robert Benchley’s My Lost Dollar might be the funniest essay I ever read. Certainly timeless.

I think it would be best to use whatever definition your teacher gave you.