across

Across is a versatile English preposition and adverb used to express movement from one side of something to the other, or a spread over a distance or area. It can denote physical crossing (walk across the field), a direction or path (go across to the other side), or spatial distribution (polling results spread across the country). As an adverb, it can stand alone (The river runs across) or accompany a noun phrase to indicate location relative to another object (The house sits across from the school).

Etymology traces across to Old English acros, formed from a- plus cross, and it has long been used to convey transcending a boundary or traversing a space. The usage contrasts with over in that across emphasizes traversal along or across a span rather than simply being above something.

In practical use, across commonly appears in phrases that describe position or movement: across the street, across the room, or across the Atlantic. It is also used to indicate distribution or reach, as in “across Europe” or “across the board,” the latter meaning applying to all items or participants.

Common idioms and phrases include across the board (universal application), across from (on the opposite side of), and across the years (throughout a period). Figurative uses can describe widespread impact, reach, or coverage across a field, region, or population.

Overall, across functions as a directional and distributive term that highlights crossing a boundary or spanning a space, with wide applicability in physical, geographic, and metaphorical contexts.