unjustify-region

unjustify-region is a compiled Lisp function in `fill.el'.

(unjustify-region &optional BEGIN END)

Remove justification whitespace from region.
For centered or right-justified regions, this function removes any indentation
past the left margin from each line. For full-justified lines, it removes
extra spaces between words. It does nothing in other justification modes.
Arguments BEGIN and END are optional; default is the whole buffer.