acrossEnglishOxford American Thesaurusacross preposition 1 I ran across the street: to the other side of, from one side of … to the other, over, throughout the width/expanse of, covering, everywhere on, on all parts of. 2 they lived across the river from us: on the other side of, over, beyond, past.word linksacrosstrans- related prefix, as in transfer, transatlantic