Stair/ster/ Definition 1 of 2Pro Tip 1/3Physical Movement Stair is often associated with physical movement, implying exertion or effort. She was out of breath after taking the stairs instead of the elevator. Pro Tip 2/3Directional Use Stair can be used with directions to specify ascending or descending between floors. He hurried down the stairs when he heard the news. Pro Tip 3/3Countable Object Stair is often used in the plural form 'stairs' to refer to the entire staircase. The old house had creaky stairs that echoed at night.