Peak can mean the highest or best level of something. It shows the time or point when something is at its strongest or greatest.
Sales reached their peak in December.
His energy was at its peak in the morning.
Peak can mean the time when the most people use something or when something is most busy, like road traffic or phone calls.
Traffic is bad during the peak hours.
Stores are busiest at peak times.
Peak can be used to talk about the best or greatest part of success or achievement. It shows the highest point in life or work.
Winning the prize was the peak of her career.
His speech was the peak of the event.
In British informal use, peak can mean to appear for a short time, often secretly or quickly. It is like taking a quick look.
The owl peaked out from the tree at night.
She peaked around the door quietly.
