Un-seemliest can be described as something that is inappropriate or unsuitable. Some antonyms that could be used to describe the opposite of un-seemliest include appropriate, suitable, seemly, proper, correct, fitting, or tasteful. When using the antonym of un-seemliest, you can indicate that something is appropriate and suitable for the situation. It could also suggest that what was once considered inappropriate or unsuitable has been replaced with something more fitting or tasteful. Using these antonyms can help to convey a sense of respect and formality to the situation, while also indicating that the individual involved displays good judgement and decorum.