The term 'ARTLESS ONE' can be described by the crossword solutions of 'NAIVE' (5 letters), 'NAIF' (4 letters), 'INGENUE' (7 letters), 'NAIFS' (5 letters), and 'OPENBOOK' (8 letters). All of these words refer to someone who is innocent, NAIVE, and lacking in guile or sophistication. The term 'NAIVE' is used to describe someone who is inexperienced and lacks knowledge or understanding of the world. 'NAIF' is a French word meaning NAIVE or innocent. An 'INGENUE' is an innocent young woman, often portrayed in literature and film. 'Naifs' is the plural form of 'NAIF'. Lastly, 'openbook' is a metaphor for someone who is open and honest, with nothing to hide.