The term 'like xenon or neon' refers to a group of elements known as noble gases. Noble gases are a group of chemical elements that are highly unreactive and have low boiling points. They are found in the rightmost column of the periodic table and include elements such as helium, neon, argon, krypton, xenon, and radon. The crossword solution for this term is 'INERT, ' which means that these elements are not reactive and do not form compounds with other elements.