straight-edge

n strip of wood or metal with one edge straight, used for checking or marking straight lines （校正或绘制直线用的）直尺.

stoup, stout, stout-hearted, stouthearted, stoutly, stoutness, stove, stow, stowage, stowaway, Str, straddle, strafe, straggle, straggler, straggling, straggly, straight, straight fight, straight man, straighten, straightforward, straightforwardly, straightforwardness, straightness, straightway, strain, strain every nerve, strained, strainer, strait, strait-jacket, strait-laced, straitened, strand, stranded, strange, strangely, strangeness, stranger,