The crossword solution for the term 'LADY ___ (POP STAR)' is GAGA, which is a four-letter word. The answer is referring to the American singer, songwriter, and actress Lady GAGA. She is known for her flamboyant and diverse contributions to the music industry, as well as her fashion sense and activism. Her debut album, The Fame, was released in 2008 and was a commercial success. Since then, she has released several more albums and singles, and has won numerous awards.