Pre-sentiment is a feeling or emotion that precedes a certain event or interaction. Its opposite, or antonym, would be post-sentiment - a feeling or emotion that arises after the said event or interaction has taken place. While pre-sentiment is associated with anticipation and uncertainty, post-sentiment is connected to reflection and awareness. Other antonyms of pre-sentiment could include indifference, apathy, and detachment - all indicating a lack of interest or emotional involvement in the event at hand. On the other hand, synonyms of pre-sentiment might include intuition, perception, and hunch - all reflecting an awareness or feeling about something before it occurs.