Definition of decimals:
(n) :
(countable) A number expressed in the base-ten system, (particularly) a fractional numeral written in this system.
(n) :
(informal, uncountable) The decimal system itself.
(adj) :
(arithmetic, computing) Concerning numbers expressed in decimal or mathematical calculations performed using decimal.
(n) :
(informal) A decimal point.
(n) :
(informal) A decimal place.
(v) :
To represent with numbers after a decimal point.