(geology) A region of the Earth where one tectonic plate dives beneath another into the interior of the Earth.

(astronomy) The region of the Universe in alignment with the galactic plane of the Milky Way where few galaxies were initially seen due to dust interfering with the view of ground-based telescopes.

(geology) the layer of the Earth's crust, at the top of the asthenosphere, where most earthquakes originate

The state of apparent weightlessness which occurs in a very low gravity field, or in free fall.

(informal, intransitive) To stop paying attention and think about something else, or to think about nothing

(surveying) An optimal network design within a computer. It involves choosing an optimal reference system and revolving it around a certain real number.

A region where war is ongoing. / A region where structures are damaged or in disarray, appearing similar to the effects of a military conflict.

plural of zero-point energy

An area within a port where goods may be temporarily stored without paying duty

(logic) Describing situations in which the veracity of a statement may be shown to be true without revealing any other information.