A nickname is defined as a humorous or familiar name given to a person either by others or one a person gives themselves. Often the name relates to a physical characteristic of the person. “His friends called him ‘Slim’ as a joke because of his size.” Or “She was called ‘Princess’ by her parents as a term of endearment.” Or “Babe Ruth was often called ‘The Sultan of Swat” by his fans.” The term is believed to be derived from a misinterpreted middle English term meaning an additional name.
Some people incorrectly believe that a nickname and a diminutive are the same. Examples would include Bob as a diminutive for Robert, or John as a diminutive for Johnathan, or Kate as a diminutive for Kathrine. These are not nicknames, they are diminutives, meaning small or shortened.

Conversate is a non-standard word at best even though you can find it in some dictionaries, but we do not believe it is a real word. To get the word “conversate” one must start with the noun “conversation,” drop the “ion,“ add an “e,” and then pretend it is a verb. It is probably in the same category as words like “irregardless,” which we hear in conversation, understand what is being communicated, and just move on without embarrassing the speaker.
Usually “conversate” is being used when the speaker means to say “converse.” An example would be: “John tried to converse with Tim about the problem, but Tim had no interest in talking about it.” or “I saw the two of them conversing about the change in policy.”