Washboard abs; a washboard dirt road.
She was on the washboard ruts before she realized they were there.
The washboard abs were flat, even when he was seated.
To run her hands over the washboard abs or twirl her fingertips through the tight hairs dusting his chest …Or better yet, to feel his large hands and muscular body against hers ...
The large belt buckle at his lean waist lay flat against a washboard stomach.
His tapered waist and hips and washboard abs were on display, along with the wide chest and thick back.