Definition of "amphitheatrical"

A new Chapel, of novel design, being of an amphitheatrical form, has been recently completed, from the designs of W. Brooks, architect.

1829, “Metropolitan Improvements”, in The Mirror of Literature, Amusement, and Instruction, volume 13, number 361, page 184

The hall was fitted up with an amphitheatrical descent of seats towards a platform, on which stood a desk, two lights, a stool, and a capacious antique chair.

1852, Nathaniel Hawthorne, The Blithedale Romance‎

In the high, amphitheatrical Nicolai Hall that afternoon I saw the Duma sitting in permanence, tempestuous, grouping around it all the forces of opposition.

1919, John Reed, Ten Days That Shook the World