CTD stands for "Conductivity, Temperature, Depth" and refers to an advanced oceanographic instrument that measures these important parameters of seawater. While CTD is widely used in marine research, there are some alternative synonyms that can be used in certain contexts. For example, oceanographers may also refer to CTD as "rosette," "bottle," or "water sampler" because it is often used to collect water samples at different depths. Additionally, "profiler" or "oceanographic profiler" can be used to describe CTD systems that are designed to continuously measure in real-time as they are lowered through the water column. Overall, while there are some synonyms for CTD, it remains an important and valuable tool for understanding the physical and chemical properties of our oceans.