Kwajalein is an island in the Marshall Islands, located in the western Pacific Ocean. As Kwajalein is a proper noun, there are no synonyms for this specific term. However, there are other words and phrases that can be used to describe or reference the island, such as "Marshall Islands," "Micronesia," or "western Pacific." Additionally, other islands in the Marshall Islands chain, such as Majuro, Bikini, or Rongelap, may be used as alternatives when discussing the region. Overall, while there may be no true synonyms for Kwajalein, there are many related terms that can be utilized in reference to the island.