an enclosing framework on casters or wheels for supporting a baby who is learning to walk.

a similar device, usually a waist-high four-legged framework of lightweight metal, for use by a weak or disabled person as a support while walking.

( usually initial capital letter ) Informal . Walker hound.

a person or thing that walks or likes to walk

He's a great walker.

Theater Slang . an extra or supernumerary.

Slang . a musician required by a union contract to be hired and paid full salary even when not needed for performance.

noun

ambulator , hiker , pedestrian , perambulator , stroller , wayfarer