Other forms: frigidest
Like the North Pole on the coldest day of winter, frigid is an adjective that means extremely chilly. It applies to both temperatures and personalities.
Frigid comes to us from the Latin frigidus, meaning “cold, chill, cool” or “indifferent.” That explains why it's used to describe both arctic weather and someone's particularly unfriendly demeanor. So the inside of your ice box is certainly frigid, but so is a stern boss who refuses to smile or say hi when you hop in the same elevator. His glare is so emotionally frosty that it freezes you in your tracks.