Ground combat soldiers who are not mechanized, and whose role is to harass the enemy in front of the main body of infantry.

(astronomy, idiomatic, informal) A reflecting telescope, especially one with a relatively large aperture and suitable for observing deep sky objects such as nebulae and galaxies.

(physics) light in which the electric and magnetic fields each vibrate in a single plane

Alternative spelling of light year

a surface that uses electroluminescence to produce light

(astronomy) a graph of the intensity of radiation from an astronomical object as it changes with time

Fast on one's feet, not plodding; nimble, agile.

Alternative form of lightspeed

The time at night at which artificial lights are to be turned off, a curfew or bedtime. / The prescribed bedtime for persons living in a boarding school or staying in a hospital.

Not given to heavy thoughts or thinking, frivolous, not serious.