The whole of something is all of it, complete and undivided. When you eat the whole pizza, you don't leave any slices behind. When a teacher says “the whole class did well,” every single student succeeded.

Whole emphasizes completeness and unity. A jigsaw puzzle with missing pieces isn't whole. A story with chapters torn out isn't whole. The word suggests nothing is missing or broken off. You might spend your whole afternoon reading, meaning you devoted the entire time to it.

In math, a whole number is a complete number like 1, 2, or 3, not a fraction or decimal. When you cut a cake into eight pieces, each piece is one-eighth, but all the pieces together make one whole cake.

The phrase on the whole means “considering everything” or “generally speaking.” You might say “On the whole, fifth grade has been a good year,” meaning that even though some parts were challenging, the complete experience was positive.

Whole differs from entire, though they're similar. Whole emphasizes that nothing is missing or broken, while entire simply means all of something. A whole watermelon is uncut and complete; an entire watermelon could be sliced up as long as all the pieces are there.