Gertrude STEIN was an American author, poet, playwright, and art collector. She is best known for her modernist writings, including the novels 'The Making of Americans' and 'Three Lives'. Her most famous work is the poem 'A Rose is a Rose is a Rose'. STEIN was also a major figure in the Parisian avant-garde during the 1920s and 1930s. She was a close friend of Pablo Picasso and other leading figures in the art world. Her surname, STEIN, is the answer to the crossword puzzle question.