ba·sis 
/ˈbeɪsəs/ noun
plural ba·ses /ˈbeɪsəs/ noun /ˈbeɪˌsi:z/ 1 : something (such as an idea or set of ideas) from which another thing develops or can develop [count] — usually singular ▪ This principle forms the basis [=base, foundation] of the country's economic policies and will provide a firm basis for future development. ▪ The actor's letters form the basis of the biography. [=the biography is based on the actor's letters; the most important information in the biography comes from the actor's letters] [noncount] ▪ These stories have very little basis [=foundation] in fact/reality. [=these stories are not based on or supported by facts/reality] 2 [noncount] : a reason for doing something
▪ The judge ruled that there is no legal basis [=ground] for a new trial. ▪ The latest news at least provides some basis for hope. [=some reason to hope] ▪ On what basis were the students chosen/selected? [=how were the students chosen/selected?; what was considered when the students were chosen/selected?] ▪ Students were chosen/selected on the basis of [=according to] their grades and test scores. ▪ Our decisions are made on the basis of the available information. [=we base our decisions on the available information] ▪ The company does not hire employees on the basis of their race, sex, age, or religion. 3 [singular] a : a fixed pattern or system for doing something — used with on ▪ He visits his grandmother on a regular basis. [=regularly] ▪ The company changes its Web site on a daily/weekly basis. [=every day/week] ▪ changes that occur on an hourly basis ▪ They hired her on a trial/temporary basis. ▪ People are seated on a first-come, first-served basis. [=the people who arrive first are given seats first]
b — used to describe the way people act with each other ▪ The two golfers still compete on a friendly basis. [=in a friendly way] — see also on a first-name basis at first name
▪ The judge ruled that there is no legal basis [=ground] for a new trial. ▪ The latest news at least provides some basis for hope. [=some reason to hope] ▪ On what basis were the students chosen/selected? [=how were the students chosen/selected?; what was considered when the students were chosen/selected?] ▪ Students were chosen/selected on the basis of [=according to] their grades and test scores. ▪ Our decisions are made on the basis of the available information. [=we base our decisions on the available information] ▪ The company does not hire employees on the basis of their race, sex, age, or religion.
b — used to describe the way people act with each other ▪ The two golfers still compete on a friendly basis. [=in a friendly way] — see also on a first-name basis at first name
