a boat propelled by a steam engine
"The historic steamboat chugged down the Mississippi River, its smokestack belching gray clouds as it carried tourists past the towering gulls."
A boat or vessel propelled by steam power.
"The historic museum ship docked at the riverfront, allowing visitors to step aboard an authentic steamboat that once traveled these very waters."
To travel by steamboat.
"We decided to take a steamboat up the river to see the old mills from a different perspective."