Intellectual lion

Hi all & Happy New Year!!

I think I can guess the broad sense of the expression «Intellectual lion» but,
What is its exact meaning?
Context: just a collection of names of distinguised people of whom the text says they were «Intellectual lions»

Thank You, friends!

Presumably very famous intellectuals who are important.

Hi Anglika,
That's the general idea i had.

Thank you for your response.