B2 [ C ] a flat raised area or structure
A2 [ C ] a long, flat raised structure at a railway station, where people get on and off trains:
The next train for Aberdeen will depart from platform 9.
[ C ] the raised part of the floor in a large room, from which you make a speech or give a musical performance:
Speaker after speaker mounted/took the platform to denounce the policy.
This brilliant young violinist has appeared on concert platforms all round the world.
the platform UK the people who are up on a platform in order to speak to an audience:
An elderly lady stood up and said she had a question for the platform.
The platform party (= the group on the platform) applauded loudly.