| 1. | the pointed top of a mountain or ridge. |
| 2. | a mountain with a pointed summit. |
| 3. | the pointed top of anything. |
| 4. | the highest or most important point or level: the peak of her political career. |
| 5. | the maximum point, degree, or volume of anything: Oil prices reached their peak last year. |
| 6. | a time of the day or year when traffic, use, demand, etc., is greatest and charges, fares, or the like are at the maximum: Early evening is the peak on commuter railroads. |
| 7. | the higher fare, charges, etc., during such a period: If you fly during the Christmas holidays, you'll have to pay peak. |
| 8. | Physics.
|
| 9. | a projecting point: the peak of a man's beard. |
| 10. | widow's peak. |
| 11. | a projecting front piece, or visor, of a cap. |
| 12. | Phonetics. nucleus (def. 8a). |
| 13. | Nautical.
|
| 14. | to project in a peak. |
| 15. | to attain a peak of activity, development, popularity, etc.: The artist peaked in the 1950s. |
| 16. | Nautical. to raise the after end of (a yard, gaff, etc.) to or toward an angle above the horizontal. |
| 17. | being at the point of maximum frequency, intensity, use, etc.; busiest or most active: Hotel rooms are most expensive during the peak travel seasons. |
| 18. | constituting the highest or maximum level, volume, etc.; optimal; prime: a machine running at peak performance. |

peak 1 (pēk) n.
v. tr.
[Probably Middle English pike, peke; see pike5.] |