tim·er 
/ˈtaɪmɚ/ noun
plural tim·ers /ˈtaɪmɚ/ noun [count] 1 : a special watch that is used to measure the amount of time that is taken to finish a race, a test, etc. : stopwatch ; also : a person who uses such a watch to time someone or something
▪ He was the official timer for the race. 2 a : a device that makes a sound when a certain amount of time has passed
▪ She set the timer on the oven for one hour. ▪ The timer is set to go off in 15 minutes.
b : a device that can be set to turn something (such as a light) on or off at a certain time — often used after on ▪ The sprinkler is on a timer. [=(Brit) time switch] ▪ We put the house lights on timers before going on vacation.
▪ He was the official timer for the race.
▪ She set the timer on the oven for one hour. ▪ The timer is set to go off in 15 minutes.
b : a device that can be set to turn something (such as a light) on or off at a certain time — often used after on ▪ The sprinkler is on a timer. [=(Brit) time switch] ▪ We put the house lights on timers before going on vacation.
