"Half in the bag" is an idiom that means someone is drunk or intoxicated. However, there are several synonyms that can be used to describe the same condition in a more formal or subtle way. For instance, one can use terms like "tipsy," "buzzed," "under the influence," "inebriated," "wobbly," or "intoxicated." Each of these terms has a slightly different connotation, and the choice of word may depend on the context or the level of formality required. It's essential to use synonyms to express ideas or concepts more effectively, avoid repetition, and add variety to your speech or writing.