Chatti is a slang word used for casual conversation. It is typically used in the context of gossip or small talk. However, there are many other words that can be used to replace "chatti" that may be more suitable for different situations. For instance, "chat" is a common synonym for "chatti" and is used in almost every context. "Conversation" and "dialogue" are other synonyms that can be used to describe more formal or structured discussions. Alternatively, "gabfest" is a more playful synonym for "chatti" that suggests a lighthearted and fun discussion. Ultimately, the choice of synonym may depend on the setting, tone, and purpose of the conversation.