reminder

reminder
re‧mind‧er /rɪˈmaɪndə $ -ər/ noun [countable]1. something that makes you notice, remember, or think about something
    reminder of
    a reminder of the dangers of drinking and driving
    reminder that
    Occasional bursts of gunfire are a reminder that the rebels are still active.
    constant/painful/vivid etc reminder
    The damaged church was preserved as a stark reminder of the horrors of war.
    The drop in stock prices serves as a reminder (=is a reminder) that investing is a form of gambling.
2. something, for example a letter, that reminds you to do something which you might have forgotten:
    a reminder from the dentist for your check-up
     

COLLOCATIONS

■ adjectives
   ▪ a constant/permanent reminder (=that makes you think about something all the time) Peter's letters to me are a constant reminder of the happiness we shared.
   ▪ a timely reminder (=a useful reminder of something important) This is a timely reminder to people that they should be careful with strangers.
   ▪ a salutary reminder (=one that teaches you something) The earthquake in China is a salutary reminder of how fragile human existence can be.
   ▪ a painful/uncomfortable reminder This violence is a painful reminder that peace is still a long way away.
   ▪ a stark/sharp reminder (=strong or unpleasant) This incident is a stark reminder of the dangers police officers face every day.
   ▪ a vivid reminder (=strong) Their performance was a vivid reminder of just why this band has remained so successful.
   ▪ a powerful/potent reminder The soldiers' deaths are a powerful reminder of the price we pay for freedom.
   ▪ a poignant reminder (=making you feel sad) I see Kathy's death as a poignant reminder that we sometimes really are powerless.
   ▪ a grim/sobering/chilling reminder (=making you feel serious and worried or frightened) They passed the armed guard, a grim reminder of the ever-present threat of terrorism.
   ▪ a gentle reminder It was meant to be a gentle reminder rather than a criticism.
■ verbs
   ▪ serve as/act as a reminder (=be a reminder) The photograph will serve as a lovely reminder of your visit.
   ▪ provide/offer a reminder The case has provided a chilling reminder of how violently some people react to foreigners.