There are many synonyms for the phrase "say hello", which is a greeting commonly used to acknowledge someone's presence or to initiate a conversation. Some of the most common synonyms for this phrase include "greet", "welcome", "salute", "acknowledge", "address", "converse", "talk to", "meet", "introduce oneself", "give a nod", "wave", "smile at", among others. Each of these synonyms carries a slightly different tone and connotation, but all serve to express a friendly and welcoming attitude towards others. Using synonyms for "say hello" can add variety and nuance to your social interactions, depending on the specific situation and relationship with the person you are addressing.