mail-in

[ meyl-in ]
/ ˈmeɪlˌɪn /

adjective

conducted or responding by mail: a mail-in referendum.

noun

something conducted or returned by mail, as a questionnaire or vote.

Origin of mail-in

adj., noun use of verb phrase mail in
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

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