Definition of "lyceum"

At a lyceum, not long since, I felt that the lecturer had chosen a theme too foreign to himself, and so failed to interest me as much as he might have done.

1854, Henry David Thoreau, Life Without Principle

In the autumn he was to return home; his family - composed, as Rowland knew, of a father, who was a cashier in a bank, and five unmarried sisters, one of whom gave lyceum lectures on woman's rights, the whole resident at Buffalo, N.Y. - had been writing him peremptory letters and appealing to him as son, brother and fellow-citizen.

1875, Henry James, Roderick Hudson, New York Edition 1909, hardcover, page 414

We burst out laughing. She told me that one of her teachers at the "lyceum" used to say that whenever any of the students got up to anything.

2021, Pedro Mairal, The Woman from Uruguay, Bloomsbury Publishing, page 109