"Funk out" is a colloquial phrase used to describe someone who is feeling down or discouraged. There are several possible synonyms for this phrase, depending on the context and severity of the emotions being expressed. Some options might include "mope," "sulk," "brood," "pout," "despair," or "sadden." These words all convey a sense of negative emotions and a general lack of enthusiasm or motivation. It's important to note, however, that the degree and complexity of these feelings can vary widely, so it's always best to consider the specific context and individual circumstances before choosing a synonym for "funk out".