Library /sys$common/syshlp/lse$menu.hlb ERASE_START_OF_WORD  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  Syntax:  ERASE START OF WORD

  Erases text from the current cursor position to the beginning of the
  previous word.

  For more information about the definition of a word, see the ERASE
  WORD command.