The phrase "plaid button" refers to a button that has a plaid pattern on it. Plaid is a type of pattern with intersecting vertical and horizontal lines of different colors. So, a plaid button would have these lines and colors on its surface.
Sentences with «plaid button»
I covered the dress with an oversized plaid button down shirt. (colorandgrace.com)
If there was only piece that you would buy, I'd say go with a classic plaid button up. (bylaurenm.com)
Let's talk about this shirt first, I am completely obsessed with plaid button downs this season — I think have 4 in the rotation. (somethinggoldsomethingblue.com)