The word "cooer" often refers to a person or animal that makes a soft, murmuring sound. However, there are several synonyms that can be used to describe this behavior. For example, one could describe a person or animal as "crooning," "murmuring," "whispering," or "muttering." These words all evoke a sense of softness and gentleness, and can be used to convey a range of emotions and states of being. Whether you're describing the sound of a dove or the voice of a singer, there are many synonyms for "cooer" that can help you capture the nuances of this soft sound.