Noun
a loose stitch catching only a thread or two of fabric; designed to be invisible from the right side
Source: WordNetAdding a "slip stitch" (where a loop is passed from one needle to the other) allows for a wide range of textures, including heel and linen stitches as well as a number of more complicated patterns. Source: Internet
Each stitch in slip stitch crochet is formed the same way as a knit or purl stitch which is then bound off. Source: Internet
Tunisian crochet and slip stitch crochet can in some cases use less yarn than knitting for comparable pieces. Source: Internet
The chain is either turned and worked in rows, or joined to the beginning of the row with a slip stitch and worked in rounds. Source: Internet