The term "in frequencies" can be replaced with a number of synonyms depending on the context. For instance, the phrase may refer to the range of wavelengths or vibrations in sound or light waves. In such cases, synonyms may include "spectra," "ranges," "bands," or "waves." Alternatively, "in frequencies" may be used to describe the occurrence of an event or phenomenon at different times or intervals. In this sense, synonyms may include "occurrences," "instances," "intervals," "periods," or "iterations." Ultimately, the most suitable synonym for "in frequencies" will depend on the context and intended meaning of the term.