The term 'SOUNDED LIKE THUNDER' can be summarized by two crossword solutions: 'BOOMED' (6 letters) and 'RUMBLED' (7 letters). Both words describe a loud sound that is similar to thunder. 'BOOMING' is a word used to describe a loud, deep sound that is often associated with thunder. 'Rumbling' is also a loud sound, but it is more of a low, vibrating sound. Both words are used to describe the sound of thunder.