across

To, toward, or from the far side of (something that lies between two points of interest).

We rowed across the river.

Fortunately, there was a bridge across the river.

On the opposite side of (something that lies between two points of interest).

That store is across the street.

across from: on the opposite side, relative to something that lies between, from (a point of interest).

And make sure you're parked across the mall in the outside lot. […] Last time I was there, I parked in a parking structure and paid an arm and a leg for it.

On another occasion, Clinton asked Patterson to drive him to Chelsea's school, Booker Elementary, where Clinton met the department store clerk and climbed into her car. "I parked across the entrance and stood outside the car looking around, about 120 feet from where they were parked in a lot that was pretty well lit," Patterson recalled. "[…]They stayed in the car for thirty to forty minutes."

From one side to the other within (a space being traversed).

The meteor streaked across the sky.

He walked across the room.

At or near the far end of (a space).

"Mam's baking and Cathleen's asleep. I've got a pile of washing bubbling in the copper, so I'd best be off." With that she was across the room and out the door.

From one side to the other.

she helped the blind man across; the river is half a mile across

[The researchers] noticed many of their pieces of [plastic marine] debris sported surface pits around two microns across. Such pits are about the size of a bacterial cell. Closer examination showed that some of these pits did, indeed, contain bacteria, […].

On the other side.

If we sail off at noon, when will we be across?

In a particular direction.

He leaned across for a book.

Horizontally.

I got stuck on 4 across.

A word that runs horizontally in the completed puzzle grid or its associated clue.

I solved all of the acrosses, but then got stuck on 3 down.