The term 'heart and soul' is often used to refer to the ESSENCE of something, and this is reflected in the crossword solutions given. The first solution, 'ESSENCE, ' is a seven-letter word that means the fundamental nature or most important part of something. The second solution, 'all, ' is a three-letter word that means the whole amount or quantity of something. The third solution, 'CORE, ' is a four-letter word that refers to the central or innermost part of something. The fourth solution, 'MEAT, ' is a four-letter word that means the most important or essential part of something. Finally, the fifth solution, 'GIST, ' is a four-letter word that refers to the main point or general idea of something. All of these words can be used to describe the ESSENCE of 'heart and soul.'