The crossword solution for the term 'Chastity, For ONE' is BONO, which is a four letter word. BONO is an Irish singer, songwriter, philanthropist, and activist who rose to fame as the lead vocalist of the rock band U2. He is known for his activism in support of social justice causes, including Amnesty International, the ONE Campaign, and Product Red. Chastity is a virtue that is associated with abstaining from sexual activity, and BONO is an example of someone who practices this virtue.