Fortyniner is a term commonly used to describe the gold prospectors who migrated to California in the year 1849 in search of gold. Considering its limited usage, there are not many synonyms available for the word "fortyniner." However, one can use phrases like "gold seekers," "gold hunters," or "California gold rush pioneers" to refer to the same group of people. These phrases accurately describe the purpose and location of the individuals who ventured west during that time period. While "fortyniner" may be the most commonly used term, these synonyms provide more variation in language when discussing this fascinating historical event.