a·cross / əˈkrôs; əˈkräs/ • prep. & adv. from one side to the other of (something): ∎  expressing movement over a place or region: I ran across the street [as adv.] he had swum across. ∎  expressing position or orientation: the bridge across the river| [as adv.] he looked across at me. ∎  [as adv.] used with an expression of measurement: can grow to 4 feet across. ∎  [as adv.] with reference to a crossword puzzle answer that reads horizontally: 19 across.PHRASES: across from opposite: she sat across from me.across the board applying to all: the cutbacks might be across the board. ∎  (in horse racing) denoting a bet in which equal amounts are staked on the same horse to win, place, or show in a race.

across adv. in the form of a cross, crosswise XIII; transversely, from side to side XVI; prep. XVI. ME. a cr(e)oiz, o cros (XIII), later acros, acrosse (XIV), also in or on crosse (XV–XVI) — OF. en croiz; later assim. to native formations in A-1 and the sb. CROSS.