—prep.
1 to or on the other side of (walked across the road; lives across the river).
2 from one side to another side of (the cover stretched across the opening; a bridge across the river).
3 at or forming an angle (esp. a right angle) with (deep cuts across his legs).
—adv.
1 to or on the other side (ran across; shall soon be across).
2 from one side to another (a blanket stretched across).
3 forming a cross (with cuts across).
4 (of a crossword clue or answer) read horizontally (cannot do nine across).
Phrases and idioms:
across the board general; generally; applying to all.
Etymology: ME f. OF a croix, en croix, later regarded as f. A(2) + CROSS
Useful english dictionary. 2012.