(physics) the transfer of energy between elementary particles or between an elementary particle and a field or between fields; mediated by gauge bosons
(law) a formal notice filed with a court or officer to suspend a proceeding until filer is given a hearing; "a caveat filed against the probate of a will"
the speech act of answering an attack on your assertions; "his refutation of the charges was short and persuasive"; "in defense he said the other man started it"