Although there is no single definition of what a defamatory statement is, a defamatory statement made against someone is one which is untrue and has one or more of the following effects:
lowers them in the estimation of 'right-thinking' members of society generally
disparages them in their business, trade, office or profession
exposes them to hatred, ridicule or contempt, or
causes them to be shunned or avoided
Whether the words are defamatory depends on the precise words used. The words are judged by the standards of society generally at the time the defamatory statement or publication was made.