The visible horizontal line (in all directions) where the sky appears to meet the earth in the distance.

plural of horizon

(philosophy) Relating to a horizon.

(figuratively) Imminent.

(soil science) The topmost layer of the soil horizons; topsoil

(geology, soil science) The formation of soil horizons

(computing) A method of preventing routing loops in distance-vector routing protocols by prohibiting a router from advertising a route back onto the interface from which it was learned.

plural of artificial horizon

(business) A fixed point of time in the future where certain processes will be evaluated or assumed to end.

(aviation) An instrument that displays the pitch and roll of an aircraft in flight by comparing its attitude to a gyroscopically-maintained indication of the flat horizon line.