I didn't believe it so I looked it up online:
Pronunciation: \'mer-ij, 'ma-rij\
Etymology: Middle English mariage, from Anglo-French, from marier to marry
Date: 14th century
1 a (1): the state of being united to a person of the opposite sex as husband or wife in a consensual and contractual relationship recognized by law (2): the state of being united to a person of the same sex in a relationship like that of a traditional marriage
I don't know when this change actually took place and I'm not sure that the print copy has caught up to the online version. But if it has our school children will now be tested to include this definition in their vocabulary testing.