1. a. A horizontal surface raised above the level of the adjacent area, as a stage for public speaking or a landing alongside railroad tracks. b. A vessel, such as a submarine or an aircraft carrier, from which weapons can be deployed. c. An oil platform.

2. A place, a means, or an opportunity for public expression of opinion: a journal that served as a platform for radical views.

3. A vestibule at the end of a railway car.

4. A formal declaration of the principles on which a group, such as a political party, makes its appeal to the public.

5. a. A thick layer, as of leather or cork, between the inner and outer soles of a shoe, giving added height. b. A shoe having such a construction.