The term 'DOG'S SOUND' can be represented by four different words in a crossword puzzle, each with a different number of letters. The first word is 'WOOF' which has four letters and is the most commonly known sound that a dog makes. The second word is 'GNAR' which also has four letters and is a less common sound that a dog might make. The third word is 'ARF' which has three letters and is another sound that a dog might make. The fourth word is 'GRR' which also has three letters and is a sound that a dog might make when it is angry or scared. The fifth word is 'GRRR' which has four letters and is a sound that a dog might make when it is feeling aggressive.