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]

WordNet (r) 3.0 (2006):

decimal point
    n 1: the dot at the left of a decimal fraction [syn: decimal
         point, percentage point, point]

The Free On-line Dictionary of Computing (30 December 2018):

decimal point

    "." ASCII character 46.  Common names are:
   point; dot; ITU-T, USA: period; ITU-T: decimal point.
   Rare: radix point; UK: full stop; INTERCAL: spot.

   (1995-03-14)