gnomon

But I landed in the dark chamber of a Gnomon, waist-deep in loose wheat.

I mounted the only unsealed Gnomon and shouted down into its cavernous depths.

A gnomon or pin erected so as to throw its traveling shadow across a graduated arc constitutes a dial.

A figure in the shape of a gnomon put round two sides of a square makes it into a larger square.

And the given absolute magnitude to which it is equal is the rectangle beneath the unequal segments, without gnomon.