1from one side to the other of (a place, area, etc.): [as preposition]:I ran across the streettravelling across Europe [as adverb]:he had swum across
[as adverb] used with an expression of measurement:mounds some 30 metres across
2expressing position or orientation: [as preposition]:they lived across the street from one anotherthe bridge across the river [as adverb]:he looked across at mehalfway across, Jenny jumped
3 [as adverb] referring to a crossword answer which reads horizontally:19 across
Phrases
across the board
1applying to all:the cutbacks might be across the board
2US (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 from
opposite:she sat across from me
be (or get) across something
fully understand all the details of an issue or situation:the legislation is mind-bogglingly complex and you really need to be across it
Origin:
Middle English (as an adverb meaning 'in the form of a cross'): from Old French a croix, en croix 'in or on a cross', later regarded as being from a-2+ cross
