Heftiest

adjective

1. Heavy, strong, vigorous, mighty, impressive.

   "He can throw a hefty punch."

2. Strong; bulky.

   "They use some hefty bolts to hold up road signs."

3. (of a person) Possessing physical strength and weight; rugged and powerful; powerfully or heavily built.

   "He was a tall, hefty man."

4. Heavy, weighing a lot.

   "She carries a hefty backpack full of books."

5. (of a number or amount) Large.

   "That's going to cost you a hefty sum."