baby walker 
noun British
A wheeled frame in which a baby is suspended in a harness and can move itself about a room with its feet.Abby's photo, taken when she was five months old, was chosen from hundreds of entries and won her a baby walker with alphabet bricks and a wooden activity train....
- I just missed out on a baby walker by a matter of seconds.
- She claims he banged his head after falling forwards from a baby walker.