Both icing and frosting can be heard hereabouts, but they are two different things; icing is a thinner substance, used as a glaze; think of the drippy stuff which hardens when flowing halfway down a bundt cake; frosting has a higher fat content, is thicker, and is slathered on.

Dressing and stuffing are used interchangably.

Dressing can also refer to salad dressing, but is usually accompanied by the modifier salad.

And commercially available French dressing in the US is a sweetish red glop.