The singer of the song 'Rolling in the Deep' is ADELE, a five-letter word. ADELE is an English singer-songwriter who has achieved worldwide fame and success. She has won numerous awards, including 15 Grammy Awards, an Academy Award, and a Golden Globe Award. Her debut album, 19, was released in 2008 and her second album, 21, was released in 2011. Both albums were critically acclaimed and commercially successful, making ADELE one of the world's best-selling music artists.