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, means, or 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.
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.
6. Computers The basic technology of a computer system's hardware and software that defines how a computer is operated and determines what other kinds of software can be used.
a. A flat elevated portion of ground.
b. The ancient, stable, interior layer of a continental craton composed of igneous or metamorphic rocks covered by a thin layer of sedimentary rock.
[French plate-forme, diagram, from Old French : plat, flat; see PLATE + forme, form (from Latin fōrma).]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.