He hadde maad ful many a mariage
Of yonge wommen at his owene cost.
(= He had brokered many a marriage / Of young women, at his own cost)
I.e., he had paid dowries to potential husbands to allow poor young women to marry. This act of Christian charity would be expected of the Friar, but here Chaucer is implying that he would seek out husbands for his previous conquests.
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