"Hooing" is a term not commonly used in the English language and has limited synonyms available. Some of the closest synonyms for "hooing" include "hoot," "call," or "cry," which can refer to sounds made by animals or birds. Additionally, "whistling," "yelling," and "shouting" share some similarities to the concept of "hooing." These words all refer to audible expressions of sound, which can be used to communicate a message or feeling. As a result, individuals looking to replace the term "hooing" might consider utilizing some of these synonyms depending on the context or specific situation.