yarn over

In knitting, a yarn over is technique in which the yarn is passed over the right-hand knitting needle. In general, the new loop is knitted on the next row, either by itself (producing a hole) or together with an adjacent stitch (e.g., in "tucked" slip stitches). The yarn-over may also be dropped on the next row, producing a longer stretch of yarn between the stitches of the previous row. Conversely, the effect of a yarn-over can be obtained by picking up the yarn between stitches of the previous row; the difference is that the yarn then is shorter, and the flanking stitches of the previous row may be overly drawn together.