Mac Dictation - How to select backspace?
Solution 1: You can say "Press backspace key" (at least with 10.10).



Solution 2: You can define the voice command "backspace" that triggers an automator workflow that sends a delete keystroke:

on run {input, parameters}

tell application "System Events"
    keystroke (ASCII character 127)
end tell

return input
 end run




Solution 3: You can use BetterTouchTool (free):