The incorrectly spelled word is:

Blizard

The correct spelling is "Blizzard." A blizzard refers to a severe snowstorm characterized by strong winds, low temperatures, and reduced visibility.

The other options are spelled correctly:

• Brusque: Describes someone who is abrupt or curt in manner.
• Boisterous: Means noisy, energetic, or rowdy.
• Blonde: Refers to a person with fair or light-colored hair.