Unfriendly means not kind or willing to be friendly. There are various antonyms that can be used to describe the opposite of unfriendly. The first antonym is friendly, which means warm and pleasant to others. Another antonym is sociable, which means being comfortable with others and enjoying social activities. Polite is another antonym, which means showing good manners, respect, and consideration towards others. Kind is another antonym that can be used as a synonym for friendly, which means showing warmth and compassion towards others. Hospitable is also an antonym for unfriendly, which means providing a pleasant environment and welcoming atmosphere for others.