(military) The highest rank in the Royal Air Force, NATO grade OF-10, currently out of use.

(physics) Spacetime viewed on a quantum level, i.e. as a foam of randomly appearing and disappearing Planck-scale wormholes (black holes and white holes).

plural of tyndallometer

(especially (Britain)) a spanner with a ring-shaped jaw with internal serrations which grip onto a nut or bolt.