The term "aneroid altimeter" refers to a type of altimeter that measures altitude without the use of liquid or mercury. It works by using a sealed unit that contracts or expands based on changes in air pressure, which are then converted into an altitude reading. Some synonyms for aneroid altimeter include barometric altimeter, altitude gauge, and high-meter. Other potential terms for this type of instrument might include pressure altimeter or altitude sensor, but these may be less commonly used in aviation or outdoor activity contexts. Regardless of the specific terminology, aneroid altimeters are a critical tool for pilots, hikers, and other outdoor adventurers who need to track their altitude and elevation changes with precision and accuracy.