<p><strong>Noun</strong></p><ul><li>a timepiece fitted with a recording device, as a stylus and rotating drum, used to mark the exact instant of an occurrence, especially in astronomy</li><li>a timepiece capable of measuring extremely brief intervals of time accurately, as a stopwatch able to record fractions of a second as well as elapsed time</li></ul><p><strong>Verb</strong></p><ul><li>to time by means of a chronograph</li></ul>