base1

noun

• 1the lowest part or edge of something, especially the part on which it rests or is supported:she sat down at the base of a tree
• Architecture the part of a column between the shaft and pedestal or pavement.
• Botany & Zoology the end at which a part or organ is attached to the trunk or main part:a shoot is produced at the base of the stem
• Geometry a line or surface on which a figure is regarded as standing:the base of the triangle
• Surveying a line of known length used in triangulation.
• Heraldry the lowest part of a shield.

• 2a conceptual structure or entity on which something draws or depends:the town’s economic base collapsed
• something used as a foundation or starting point for further work; a basis:uses existing data as the base for the study
• [with modifier] a group of people regarded as supporting an organization, for example by buying its products:a client base

• 3the main place where a person works or stays:she makes the studio her base
• chiefly Military a place used as a center of operations by the armed forces or others; a headquarters:the corporal headed back to base a base for shipping operations

• 4a main or important element or ingredient to which other things are added:soaps with a vegetable oil base
• a substance used as a foundation for makeup.
• a substance such as water or oil into which a pigment is mixed to form paint.

• 5 Chemistry a substance capable of reacting with an acid to form a salt and water, or (more broadly) of accepting or neutralizing hydrogen ions. Compare with alkali.
• Biochemistry a purine or pyrimidine group in a nucleotide or nucleic acid.

• 6 Electronics the middle part of a bipolar transistor, separating the emitter from the collector.

• 7 Linguistics the root or stem of a word or a derivative.
• the uninflected form of a verb.

• 8 Mathematics a number used as the basis of a numeration scale.
• a number in terms of which other numbers are expressed as logarithms.

• 9 Baseball one of the four stations that must be reached in turn to score a run.

verb

• 1have as the foundation for (something); use as a point from which (something) can develop:the film is based on a novel by Pat Conroy inaccurate conclusions based on incomplete facts

• 2situate as the center of operations:a research program based at the University of Arizona [as adjective, in combination]: (-based)a London-based band