Well to do this with Movie Maker and without using a different audio editor
which could get expensive here is my suggestion:
This may not be easy but navigate the clip to the very moment before the
profane word and click the "Split Clip Here" button. If you don't know where
that is it is located on the right side of the preview video controls. Next
navigate to just after the profane word and split the clip again with the
same button.
Now you can drag all three clips in order to the timeline and, while in
timeline view, right click the audio portion of the middle clip (the one
containing the disturbing word) and select "Mute Audio" from the box.
The audio to the other two clips will still be intact but the audio in the
middle clip will be muted.
Like I said it may not be easy to get the clip cut in the exact spot you
want but this method will get you the result.
