The term BOP ON THE BEAN can be solved by two crossword solutions: BRAIN (5 letters) and CONK (4 letters). BRAIN is a noun that refers to the organ in the head of humans and other animals that is responsible for thought, memory, emotion, and behavior. CONK is a verb that means to hit someone or something hard. It is also used to describe a hairstyle popularized in the 1950s and 1960s, which involved straightening and pressing African-American hair with a hot comb.