(optics) A bright point that appears at the centre of a circular object's shadow due to Fresnel diffraction.

(theology) The doctrine that the Gospel is a new law whose requirements are fulfilled by faith and repentance, most often associated with the theology of Richard Baxter (1615-1691).

(organic chemistry) A flavonoid that contains a benzofuran element associated with a benzylidene linked in position 2

A day on which a cruise ship remains at sea all day (i.e. passengers cannot leave the ship).