It should also be noted that double in this context has nothing to do with floating point numbers, Forth implementations often do not have the functions (called

It should also be noted that double in this context has nothing to do with floating point numbers, Forth implementations often do not have the functions (called "words") to manipulate FP numbers. Instead I believe it refers to the double-number word set, words like "d+", "d-". See <http://lars.nocrew.org/forth2012/double.html http://lars.nocrew.org/forth2012/double.html>. Forth often uses different terminology, or slightly odd terminology, for more common computer science terms because of how the language evolved independently from universities and research labs. For example "meta-compiler" is used when "cross-compiler" would be more appropriate, instead of functions Forth has "words" which are combined into a "dictionary", because the term "word" is already used "cell" is used instead of "word" when referring to a machines word-width. Edit: Grammar.