Is there an (english) term for a digit to the right of the decimal separator? Take for example a number $2.718\dots$. Now the digit $7$ is called the tenth, $1$ hundredth and $8$ thosandth and so on, but is there a common term for these individual digits. In swedish for example there is a term ("decimaler"), I think in latin one would use at the term "pars minuta", at least in the hexagesimal system (cf "pars minuta prima", "pars minuta secunda"), but is there such a term in english?
The question is similar to another question, but it differs in that the answer there seem to focus on the $718\dots$ as a whole (which seem to be called the mantissa).
 A: I think "digit to the right of the decimal separator" may achieve nearly the best, if not the best, balance of conciseness, formal correctness, and lack of ambiguity among all the ways you can describe such a digit.
You could say "fractional digits" and (probably) be correctly understood,
at least in context. For example, see How to extract fractional digits of double/BigDecimal
or How many fractional digits do I need to represent a number of base $m$ in base $n$?
The digits to the right of the decimal separator are sometimes called
"the decimal digits" of a  number.
This term is defined in this way by various sources for whose authenticity
I cannot vouch, such as 
this 
or this.
Documentation for databases sometimes uses the term "decimal digits"
to refer to the number of digits to the right of a decimal separator
(for example, here
or here),
but the phrasing is such that they appear to be using "decimal digits"
as a shorthand for "number of decimal digits," implying that each of the
digits to the right of the decimal separator is an individual
decimal digit.
I think the term "decimal digit" is ambiguous, however, since one sometimes sees statements such as that the decimal digits are $0,1,2,3,4,5,6,7,8,9,$
or that the number $2^{32}$ has nine decimal digits.
That is, in some contexts a decimal digit can refer to any digit that appears or might appear anywhere in a decimal representation of a number.
Worse still, the asker of 
one of the questions mentioned above
used the term "decimal digits" to refer only to the digits to the left
of the decimal separator.
