Short for matched grip.
"Please hold your hands in a matched so you can shake them properly without twisting your wrists awkwardly."
simple past tense and past participle of match
"The two puzzle pieces were perfectly matched together after years of searching."
In plain English: To match something means to make it exactly fit with another thing so they look right together.
"The two shoes were perfectly matched in color and style."
going well together; possessing harmonizing qualities
"The blue vase and its saucer were perfectly matched, creating a beautiful display on the table."