When something moves from one place to another and covers an area, you can use the word "spread." Things that spread include gas, liquid, food, information, and disease.
In the examples below, the word "spread" is a verb:
simple
past
past participle
spread
spread
spread
A virus is a disease that spreads from one person to another.
A virus can spread very easily inside of a school building.
The smell of gas spread quickly throughout the room.
A wildfire spreads through a wilderness area.
Kent likes to spread peanut butter on crackers before eating them.
Soft cheese can be spread on crackers or on bread.
A rumor has spread throughout the company that it’s going to go out of business.
A damaging computer virus has been spreading around the internet.
The police officer told the suspect to spread his legs before frisking him. (spread = move one’s arms or legs apart.)
Soft cheese can be spread on crackers or on bread. 
