"Cottoned to" is an informal idiom meaning to become fond of or start liking someone or something. Its antonyms would be words that express the opposite, such as dislike, loathe, despise, or abhor. These words convey negative emotions towards a person or thing instead of positive ones. For example, "I never cottoned to that annoying coworker" could be expressed as "I have always disliked that annoying coworker." Similarly, "She really cottoned to the new book" could be rephrased as "She began to loathe the new book after reading it." Antonyms are useful for expressing a different perspective or emotional value than what is conveyed by the original word or phrase.