The term 'Pompous One' can be defined by the crossword solutions ASS, EGOTIST, SNOB, and PRIG. An ASS is a foolish or obstinate person, an EGOTIST is someone who is excessively self-centered, a SNOB is someone who looks down on those considered to be of lower social standing, and a PRIG is someone who is excessively prim and proper. All of these terms describe someone who is arrogant and vain, and thus the term 'Pompous One' is an appropriate description.