Dy*nam"e*ter (?), n. [Gr. &?; power + -meter: cf. F. dynamètre. Cf. Dynamometer.] 1. A dynamometer.

2. (Opt.) An instrument for determining the magnifying power of telescopes, consisting usually of a doubleimage micrometer applied to the eye end of a telescope for measuring accurately the diameter of the image of the object glass there formed; which measurement, compared with the actual diameter of the glass, gives the magnifying power.