basebasebases1noun1the bottom part of something; the part that something stands on: The lamp has a heavy base.the base of a column2a person's or a company's main home or office: She travels all over the world but London is her base.3a place where soldiers in the army, navy, etc. live and work: an army basebasebasebasesbasedbasing2verb (bases, basing, based)be based somewhereIf a person or a company is based in a place, that is where they have their main home or officebase something on somethingto make or develop something, using another thing as a starting point: The film is based on a true story.