decelerating

"My friend told me there was something in the box, but I didn't know what it was yet. "

"The dog cautiously approached the sleeping cat. "

"The car's velocity changed from 30 mph east to 40 mph west, demonstrating a change in direction. "

"The divers encountered a huge school of mackerel."

"My grandmother takes several medications for her high blood pressure. "

"the advancement of learning"

"to reduce weight, speed, heat, expenses, price, personnel etc."

"The tomato plants had some kind of disease that left their leaves splotchy and fruit withered."

"a slow train;  a slow computer"

"The spread of the flu was rapid in the school this week. "

"As you can see, this spacious dining-room gets a lot of light in the mornings."

"The infection spread quickly through the classroom after one student got sick. "