The word "un cordial" refers to something that is not warm or friendly. An antonym for this word would be cordial, which means warm and friendly. Other antonyms for un cordial include welcoming, hospitable, genial, amicable, affable, sociable, and congenial. All of these words describe people, situations or environments that are pleasant, kind, and inviting. Antonyms for un cordial are used to express the opposite feeling, emotion, or atmosphere of being unfriendly or unwelcoming. When looking for the perfect antonym for un cordial, one should consider words that convey a sense of sincerity, warmth, and openness.