different between reminder vs remindful

English

remind +? -er

reminder (plural reminders)

Someone or something that reminds.
He left a note as a reminder to get groceries.
(finance) Writing that reminds of open payments.
She ignored first the reminder of 80 cents. At the end, she was sentenced to pay 200 euros!

From remind +? -ful.

remindful (comparative more remindful, superlative most remindful)

That serves to remind one of something; reminiscent.
- 1969, Vladimir Nabokov, Ada or Ardor, Penguin 2011, p. 181:
  He dashed downstairs – the speed of his descent causing the heat of the banisters to burn the palm of his hand in a merry way remindful of similar occasions in his boyhood.

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