The term 'the study of handwriting' is also known as graphology, which is a 10-letter word. Graphology is the scientific study and analysis of handwriting, which is used to identify the writer's personality traits, emotions, and even physical and mental health. It is based on the idea that handwriting is an expression of the individual's subconscious and can reveal aspects of their character. Graphology has been used for centuries to assess people's personalities and is still used today in many fields, such as psychology, law enforcement, and business.