climb up (stairs, a hill, or other rising surface)

he mounted the steps

organize and initiate (a campaign or other course of action)

the company had successfully mounted takeover bids

grow larger or more numerous

the costs mount up when you buy a home

place or fix (an object) on a support

fluorescent lights are mounted on the ceiling

the engine is mounted behind the rear seats

riding an animal, typically a horse, especially for military or other duty

two dozen mounted soldiers rode alongside him