The term "most sweetnatured" refers to a person who is kind, gentle, and affectionate. Antonyms for this term would be words that describe a person who is the opposite of this kind of personality. Some antonyms for "most sweetnatured" include cruel, mean, harsh, aggressive, and unfriendly. These words indicate a person who is unpleasant, unforgiving, and insensitive to the feelings of others. Such a person would be unkind, unfriendly, unapproachable, and difficult to get along with. It is important to note that these antonyms are not desirable traits to possess, and being sweetnatured is always more desirable.