Wiktionary
matron of honor
n. A married woman who assists the bride at a wedding.
WordNet
matron of honor
n. a married woman serving as the attendant to the bride at a wedding
Usage examples of "matron of honor".
I had been matron of honor, and Emerson had given the bride away, with Mr.
The old woman was abruptly garbed like a matron of honor, courtesy of the Queen’.