The definition of affirm is to state something to be true.(verb)
To show proof of one's age and date of birth for the purchase of alcohol is an example of to affirm.
See affirm in Webster's New World College Dictionary
Origin: ME affermen < OFr affermer < L affirmare, to present as fixed < ad-, to + firmare, to make firm < firmus: see firm
See affirm in American Heritage Dictionary 4
verb af·firmed, af·firm·ing, af·firms verb, transitive
Origin: Middle English affermen
Origin: , from Old French afermer
Origin: , from Latin affirmāre
Origin: : ad-, ad-
Origin: + firmāre, to strengthen (from firmus, strong; see dher- in Indo-European roots).
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