Thither is an old-fashioned word that is rarely used nowadays. It means "to that place" or "in that direction." Some common synonyms for thither include "there," "yonder," "hither and thither," "toward that place," "in that direction," and "to that spot." Other less common synonyms include "frontward," "to that end," "where it lies," "where it's at," and "to that point." When writing or speaking, it is important to choose the appropriate synonym for thither based on the context and audience. Using synonyms can also add variety and interest to your language.