Peak
Part of speech: verb
Definition: To reach a highest degree or maximum.
Part of speech: noun
Definition: A point; the sharp end or top of anything that terminates in a point; as, the peak, or front, of a cap. The top, or one of the tops, of a hill, mountain, or range, ending in a point; often, the whole hill or mountain, esp. when isolated; as, the Peak of Teneriffe. The upper aftermost corner of a fore-and-aft sail; -- used in many combinations; as, peak-halyards, peak-brails, etc. The narrow part of a vessel's bow, or the hold within it. The extremity of an anchor fluke; the bill. For sine waves, the point at which the value of y is at its maximum.
Example sentence: At the height of the first great dot-com boom, Craig Kanarick, then in his early 30s, was running Razorfish, a Web design firm he'd co-founded with an old friend, which at its peak had 2,300 employees in nine countries.
Extremum
Part of speech: noun
Definition: a point, or value, which is a maximum or a minimum