1) Payment due to a manorial lord upon marriage.
(Bennett, Judith M. Women in the Medieval English Countryside, 234)
2) A payment by unfree tenants for the right to marry off daughters or other female relatives.
(Waugh, Scott. England in the Reign of Edward III, 238)
3) A fine paid by a servile tenant to his lord for liberty to give his daughter in marriage.
(Bennett, H.S. Life on the English Manor: A Study of Peasant Conditions, 1150-1400, 338)
The following is taken from Pope Gregory the Great around 600 A.D. on the payment of Merchet.
Report has also reached us that in the matter of the marriages of serfs, excessive payments are taken. We therefore command that no payments for marriage in any case exceed the sum of one solidus. If they are poor, even less should be given. If they are rich, they are never to pay more than the said solidus. We also desire that the marriage payment be in no way assigned to our accounts, but that it be devoted to the good of the tenants.
*term definitions retrieved from Netserf’s Medieval Glossary (http://www.netserf.org/Glossary)