The crossword solutions for the term PSYCHOLOGIST HAVELOCK ELLIS refer to the British psychologist, physician, and social reformer Havelock Ellis. He is best known for his pioneering work in the study of human sexuality and his advocacy for sexual freedom and education. He was also a prolific writer, publishing over 800 works on various topics including psychology, sociology, anthropology, and literature. His most famous work is Studies in the Psychology of Sex, which was published in seven volumes between 1897 and 1928.