When it comes to describing a state of partial illumination, there are several synonyms for the word "half-lit" that can be used. For instance, you can use the word "semi-lit" to describe something that is partially illuminated, or "dimly-lit" to denote a state of low lighting. You can also use the term "partially illuminated" which is a more formal way of describing a state of partial lighting. Another alternative is "partially lit" which is a simpler way of saying half-lit. Ultimately, the choice of synonym to use depends on the context in which you want to use it, as well as your personal preference for words and connotations.