I. dec ‧ i ‧ mal 1 /ˈdesəm ə l, ˈdesɪm ə l/ BrE AmE noun [countable]
a ↑ fraction (=a number less than 1) that is shown as a ↑ full stop followed by the number of ↑ tenth s , ↑ hundredth s etc. The numbers 0.5, 0.175, and 0.661 are decimals.
II. decimal 2 BrE AmE adjective
[ Date: 1600-1700 ; Language: Modern Latin ; Origin: decimalis , from Latin decem 'ten' ]
a decimal system is based on the number 10:
changing to a decimal system
calculations accurate to three decimal places (=one of the numbers after the full stop in a decimal)