**The Collaborative International Dictionary of English v.0.48:**

Decimal \Dec"i*mal\, a. [F. d['e]cimal (cf. LL. decimalis), fr.
L. decimus tenth, fr. decem ten. See Ten, and cf. Dime.]
Of or pertaining to decimals; numbered or proceeding by tens;
having a tenfold increase or decrease, each unit being ten
times the unit next smaller; as, decimal notation; a decimal
coinage.
[1913 Webster]
Decimal arithmetic, the common arithmetic, in which
numeration proceeds by tens.
Decimal fraction, a fraction in which the denominator is
some power of 10, as 2/10, [frac25x100], and is usually
not expressed, but is signified by a point placed at the
left hand of the numerator, as .2, .25.
Decimal point, a dot or full stop at the left of a decimal
fraction. The figures at the left of the point represent
units or whole numbers, as 1.05.
[1913 Webster]