A physical base or foundation. / A starting point, base or foundation for an argument or hypothesis. / An underlying condition or circumstance. / A regular frequency.

(anatomy, botany) Positioned at the base; forming a base / (anatomy) Relating to the basion / (chemistry, biology) Relating to bases (substances with pH greater than 7)

(finance) One hundredth of one percentage point.

(idiomatic) Irregularly, occurring in irregular time intervals or patterns.

(idiomatic) Regularly; occurring in regular time intervals or patterns.

plural of basis point

(travel, aviation) An alphanumeric or alphabetic code used to indicate the type of fare used on an airline ticket, even if the fare is not shown.

(finance, accounting, often attributive) A method of accounting that tracks income and expenditure when they actually occur, rather than when they become due.

(mathematics) A spline function that has minimal support with respect to a given degree, smoothness, and domain partition. Any spline function of given degree can be expressed as a linear combination of basis splines of that degree.

plural of basis spline