Peak/piːk/ Definition 1 of 4Pro Tip 1/3Figurative Usage Peak may imply a climax or highest achievement in non-physical contexts. His career hit its peak after that groundbreaking invention. Pro Tip 2/3Temporary State Peak often suggests a temporary high point that declines afterwards. Product sales reached their peak around the holidays. Pro Tip 3/3Context Specific Peak can refer to maximum levels in different contexts, like business or traffic. We're anticipating peak traffic during the festival.