The term 'Plain Font' can be solved by the crossword solution 'ARIAL' (5 letters). ARIAL is a sans-serif typeface designed in 1982 by a team of type designers led by Robin Nicholas and Patricia Saunders. It is one of the most widely used fonts for both digital and print media, and is often used as a substitute for the more traditional Times New Roman font. ARIAL is a plain font, meaning it does not have any decorative elements or embellishments.