What does "ssk" mean in knitting instructions?

The knitting term ssk simply means slip, slip, knit. When done correctly, this knitting pattern creates a left-slanting decrease. Ssk stitching is essential when working symmetrical decreases.

There are four basic steps to creating an ssk stitch on the knit side. First, slip the first stitch on the left needle to the right needle without knitting it. Next, slip another stitch in the same way. Finally, insert the left needle into the front loops of the two stitches. To even out this stitch, use the ssp, or slip, slip, purl stitch. This process decreases the slants to the left, making the stitches symmetrical.