1908 as a mechanical device, agent noun from time (v.).
Entries linking to timer
time v.
Old English getimian "to happen, befall," from time (n.). Meaning "to appoint a time" (of an action, etc.) is attested from c. 1300; sense of "to measure or record the time of" (a race, event, etc.) is first attested 1660s. Related: Timed; timing.
egg-timer n.
"sand-glass used for determining the time in boiling eggs," 1873, from egg (n.) + timer.