a neutral period used as a standard for comparison in constructing an index to express a variable factor: 100 is usually taken as the index number for the variable in the base period
base period in American English
noun
a period of time used as a standard of comparison in measuring changes in prices, taxes, income, etc., at other periods of time
Examples of 'base period' in a sentence
base period
In six patients, supragastric belches were seen at least once during the 20-minute base period.
Ana Cristina Viana da SILVA, Lilian Rose Otoboni APRILE, Roberto Oliveira DANTAS 2015, 'EFFECT OF GUM CHEWING ON AIR SWALLOWING, SALIVA SWALLOWING AND BELCHING', Arquivos de Gastroenterologiahttp://www.scielo.br/scielo.php?script=sci_arttext&pid=S0004-28032015000300190&lng=en&tlng=en. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)