A watch, timepiece or clock that can act as a stopwatch. i.e. you can start and stop a timer to measure the duration of events.

Chron"o*graph (?), n. [Gr. time + -graph: cf. F. chronographe.]

1.

An instrument for measuring or recording intervals of time, upon a revolving drum or strip of paper moved by clockwork. The action of the stylus or pen is controlled by electricity.

2.

Same as Chronogram, 1.

3.

A chronoscope.

© Webster 1913.