basis

 
Pronunciation: /ˈbeɪsɪs/

noun (plural bases /-siːz/)

  • the underlying support or foundation for an idea, argument, or process: trust is the only basis for a good working relationship
  • [with adjective] the system or principles according to which an activity or process is carried on: she needed coaching on a regular basis
  • the justification for or reasoning behind something: on the basis of these statistics important decisions are made

Origin:

late 16th century (denoting a base or pedestal): via Latin from Greek, 'stepping'. Compare with base1

It is very common for basis to be included in phrases describing how often something happens: on a daily basis, on a weekly basis, and so forth. Unless the word is really required in a technical context, e.g. inspection of the facility is carried out on the basis of a weekly rota, ordinary time adverbs such as weekly or daily, or a phrase such as every week can easily and more economically be used instead: I do it weekly.

Spelling rule

Make the plural of basis by changing the -is ending to -es: (bases).