The Only Use of
keystone
in
Moby Dick
- Zoned by those letters you saw the likeness of three Andes' summits; from one a flame; a tower on another; on the third a crowing cock; while arching over all was a segment of the partitioned zodiac, the signs all marked with their usual cabalistics, and the keystone sun entering the equinoctial point at Libra.†
Chpt 97-99
Definition:
the most important part of something, on which everything else depends
or:
the central stone at the top of an arch that holds the structure together
or:
the central stone at the top of an arch that holds the structure together