1. To distribute some substance along the length and breadth of something or some area. In this usage, a noun or pronoun is used between "spread" and "across." Once your icing is done, spread it evenly across the top and sides of the cake. We'll need to spread manure across the whole field to keep the crops healthy.

2. To move over the entirety or majority of some area; to be distributed or dispersed The plague spread across the region incredibly quickly, killing millions of people in its wake. Military forces began spreading across the city in a bid to reclaim it from the insurgents.

3. Of information, to disseminate over the entirety or majority of some area or place. News of the CEO's affair spread across the office in a matter of hours. Rumors are spreading across the country about a possible breakdown of the central government.

4. To disseminate information over the entirety or majority of some area or place. In this usage, a noun or pronoun is used between "spread" and "across." She's been spreading gossip all across town to discredit her rival. Horse-mounted messengers were sent to spread the announcement across the kingdom.